AMBRA1 and melanoma: Furthermore, downregulation of AMBRA1 (and loricrin) in the epidermis overlying a cutaneous melanoma suggests the existence of a paracrine mechanism by which melanoma cells are able to control AMBRA1 levels and influence keratinocyte differentiation, consistent with previous observations of hyperplasia with disturbed keratinocyte differentiation in the epidermis overlying melanomas.19