CDKN2A and nervous system neoplasm: Nevertheless, a proportion of melanoma families linked to the 9p21 locus do not harbour germline mutations of INK4a-ARF, and three large deletions have been reported in hereditary predisposition to melanoma and nervous system tumours, two involving both p16INK4a and p14ARF (Bahuau et al, 1998), and one restricted to exon 1β of p14ARF (Randerson-Moor et al, 2001).