PTEN and melanoma: In the last decades, other variable genomic alterations have been identified in melanoma initiation and progression, such as the mutation of Ras-related C3 botulinum toxin substrate 1 (RAC1), TERT, Kirsten rat sarcoma viral oncogene homolog (KRAS), Erb-b2 receptor tyrosine kinase 2/4 (ERBB2/4), cyclin-dependent kinase inhibitor 2A (CDKN2A), tumour protein 53 (TP53), and phosphatase and tensin homolog (PTEN), along with mitogen-activated protein kinase kinase 1 and 2 (MAP2K1/2) [56,81,82,83,84,85] (Table 2).