The loss of the nuclear expression of the breast cancer type 1 susceptibility protein (BRCA1) and the associated protein-1 (BAP1), a deubiquitylase that acts as a tumor suppressor molecule in mesothelioma and other neoplasms [13,14,15,16,17], and the loss of the cytoplasmic expression of methylthioadenosine phosphorylase (MTAP), a surrogate marker of the CDKN2A (p16) alteration, were recently tested in SM and SC with various results [17,18,19]. Here, CDKN2A is linked to mesothelioma.