Sim2s expression patterns correlate with a subset of milk protein genes during lactation. (A-E) Total RNA isolated from V8, L1, L4 and L7 FVB mammary glands (n=5 animals per group) was used for qRT-PCR analysis of (A) Sim2s, (B) Wap, (C) Csn2, (D) Lalba and (E) Expi expression. Cldn7 was used to normalize all mammary qRT-PCR data.