Exhibit 10.2 MORTGAGE LOAN PURCHASE AGREEMENT

                                                                    Exhibit 10.2

                        MORTGAGE LOAN PURCHASE AGREEMENT

               This Mortgage Loan Purchase Agreement (the "Agreement"), dated as
of August 30, 2007, is between Wells Fargo Asset Securities Corporation, a
Delaware corporation (the "Company"), and Wells Fargo Bank, N.A., a national
banking association (the "Seller" or "Wells Fargo Bank").

               The Company and the Seller hereby recite and agree as follows:

               1. Defined Terms. Terms used without definition herein shall have
the respective meanings assigned to them in the Pooling and Servicing Agreement,
dated as of August 30, 2007 (the "Pooling and Servicing Agreement"), among the
Company, Wells Fargo Bank, as master servicer (the "Master Servicer"), and HSBC
Bank USA, National Association, as trustee (the "Trustee"), relating to the
issuance of the Company's Mortgage Pass-Through Certificates, Series 2007-AR4
(the "Certificates") or, if not defined therein, in the underwriting agreement,
dated February 15, 2006, and terms agreement, dated August 6, 2007 (together,
the "Underwriting Agreement"), among the Company, Wells Fargo Bank and Lehman
Brothers Inc. ("Lehman Brothers"), or in the purchase agreement, dated May 10,
2004, and the purchaser terms agreement, dated August 6, 2007 (together, the
"Purchase Agreement"), among the Company, Wells Fargo Bank and Lehman Brothers.

               2. Assignment of Servicing Agreements. The Seller agrees to sell,
and the Company agrees to purchase, the mortgage loans (the "Mortgage Loans")
listed on the Mortgage Loan Schedule and all of the Seller's interest with
respect to the Mortgage Loans as the owner in, to and under each Servicing
Agreement.

                3. Purchase Price; Purchase and Sale. The purchase price (the
"Purchase Price") for the Mortgage Loans shall consist of $[________] payable by
the Company to the Seller on the Closing Date in immediately available funds.

               Upon payment of the Purchase Price, the Seller shall be deemed to
have transferred, assigned, set over and otherwise conveyed to the Company all
the right, title and interest of the Seller in and to the Mortgage Loans
including all interest and principal received or receivable by the Seller on or
with respect to the Mortgage Loans after the Cut-Off Date (and including
scheduled payments of principal and interest due after the Cut-Off Date but
received by the Seller on or before the Cut-Off Date and Principal Prepayments
received or applied on the Cut-Off Date, but not including payments of principal
and interest due on the Mortgage Loans on or before the Cut-Off Date), together
with all of the Seller's right, title and interest in and to the proceeds of any
related title, hazard, primary mortgage or other insurance policies, the
Seller's right to receive amounts, if any, payable on behalf of any Mortgagor
from the Subsidy Account relating to any Subsidy Loan, all of the Seller's
rights described in Section 2 above, and all other property and rights described
in the first paragraph of Section 2.01(a) of the Pooling and Servicing
Agreement. The Company hereby directs the Seller, and the Seller hereby agrees,
to deliver to the Trustee or Custodian on behalf of the Trustee, all documents,
instruments and agreements required to be delivered by the Company to the
Trustee under the Pooling and Servicing Agreement; including, without
limitation, the documents required to be delivered

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under Section 2.01(a) of the Pooling and Servicing Agreement; and upon the
occurrence of a Document Transfer Event, the documents required to be delivered
under Section 2.01(b). The Seller further agrees to deliver such other
documents, instruments and agreements as the Company or the Trustee shall
reasonably request.

               4. Representations and Warranties; Covenants. The Seller hereby
represents and warrants to the Company that (i) the Company's representations
and warranties to the Trustee pursuant to Section 2.03(b) of the Pooling and
Servicing Agreement are true and correct, as of the date thereof, and (ii)
Seller has not dealt with any broker, investment banker, agent or other person
(other than the Company and Lehman Brothers) who may be entitled to any
commission or compensation in connection with the sale of the Mortgage Loans.
The Seller hereby agrees to cure any breach of such representations and
warranties in accordance with the terms of the Pooling and Servicing Agreement.

               The Seller hereby agrees to continue to pay on behalf of the
Company and its successors and assignees, promptly as they become due, any
lender-paid primary mortgage insurance premiums ("LPMI Premiums") with respect
to any lender-paid primary mortgage insurance policy (an "LPMI Policy") on each
Mortgage Loan so insured as of the Cut-Off Date, until such Mortgage Loan has
been paid in full or otherwise liquidated; provided, however, that the foregoing
obligation of the Seller shall terminate with respect to all such Mortgage Loans
in the event that either (i) another entity acceptable to the insurers of such
LPMI Policies (the "LPMI Insurers") and the rating agencies rating the
Certificates undertakes to pay such LPMI Premiums, or (ii) the Seller pays
one-time premiums to such LPMI Insurers such that all outstanding LPMI Policies
will remain in force until the related Mortgage Loans have be