Our finding that TGF-β2 is upstream from Ki67 expression and MAPK activation lends further support to the notion that hair follicle keratinocytes at this early stage of development react to TGF-β2 signaling in a fashion opposite to that typically expected for TGF-β factors. This said, based upon pSMAD2 immunohistochemistry, the immediate steps of downstream signaling appeared to be intact. Thus, we surmise that the proliferative outcome is likely to be rooted in differences in the repertoire of activated SMAD target genes. In this regard, the positive effects of TGF-β2 on proliferation within the hair bud may be more analogous to what has been seen in progression of squamous cell carcinoma to metastatic carcinoma [43] rather than that typically observed for keratinocytes [44,45,46].