TP53 and incontinentia pigmenti: In the case of TP53 mutations, there were 2/6 (33.3%) cases in which mutations identical to those observed in SCC were already present in the IP, 2/6 (33.3%) cases in which no TP53 mutation was observed in the IP while SCC had one, and 2/6 (33.3%) cases in which TP53 mutation was not observed in neither IP nor SCC.