**10. Concluding remarks**

Analyses of mutant mice with epidermal loss of aPKCλ have clarified a novel function of aPKCλ in HFSC maintenance. aPKCλ influences HFSC maintenance through the regulation of oriented cell division among HFSCs in the bulge (intrinsic mechanism) and the regulation of the expression of quiescence-inducing Fgf18 and Bmp6 (paracrine mechanism). Identification and evaluation of the downstream effectors of aPKCλ in HFSC maintenance will provide further insight into the mechanism of hair loss.
