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CSFB Mortgage Securities Corp. Commercial Mtge Pass-Through Ctfs. 2003-C4 -- Moody's upgrades one and affirms one class of CSFB 2003-C4

The rating on Cl. L was upgraded based primarily on an increase in credit support resulting from loan paydowns and amortization. The rating on the IO class, Cl. A-X, was affirmed based on the credit quality of the referenced classes.