Previous investigations in p53 wild-type A375 melanoma cells had revealed that nutlin-3 pre-treatment had resulted in a p53-mediated cell cycle arrest that protected these cells from tozasertib-induced anti-cancer effects while tozasertib pretreatment or simultaneous combined tozasertib and nutlin-3 treatment had resulted in enhanced combined anti-cancer effects [39]. This evidence concerns the gene TP53 and melanoma.