TGFα null and wa-1 keratinocytes transformed with the v-H-ras oncogene and grafted onto nude mice give rise to skin tumors (mostly papillomas) similar to that of keratinocytes from BALB/c or C57BL mice (wild-type counterparts to wa-1 or TGFα null, respectively) [113]. The gene discussed is TGFA; the disease is papilloma.