TP53 and Merkel cell skin cancer: UM-MCC9 and UM-MCC34 both harbor frameshift deletions in TP53 (UM-MCC9: chr17.7577070.G > -, UM-MCC34: chr17.7579518.CTTCA > -), and UM-MCC32 a frame-shift deletion in RB1 (chr13.48919254.CCAGTACCAAAGTTGATAAT > -); the inhibition of both tumor suppressors plays an important role in MCC carcinogenesis [4,5,6,7,8,9,11,12,13,14,26,27,28].