The growth of human hair in nude mice has been studied more than the growth of mouse hair in nude humans. This study reports some of the early work about the first of those categories:
“The Growth of Human Hair in Nude Mice,” Dominique Van Neste, Dermatologic Clinics, vol. 14, no. 4, 1996, pp. 609-617. The author reports:
we thought of transplanting small fragments of a primitive skin melanoma onto nude mice. Leaving the fragments in place for enough time, a tumor eventually developed. By collecting the expanded tumor, we also successfully grew the tumor cells in vitro and established a cell line… [We started] a pragmatic approach in the late 1980s with the purpose of producing human hair under conditions as close as possible as those prevailing in vivo and in situ.