BMP2 and hydrops fetalis: Various signaling pathways have been identified as influential to hair follicle (HF) development, including Fgf signaling during the telogen-to-anagen transition [6], Tgf-β1 and Tgf-β2 induction of SHFs into catagen [7], variations in Bmp2 expression from late telogen to anagen [8], and Wnt/β-catenin signaling, which regulates cell proliferation in the hair matrix and dermal papilla [9].