One study took a candidate gene approach with 20 cutaneous melanomas and found no variants mutations in the key melanoma drivers, specifically BRAF, NRAS, PTEN, KIT, GNAQ, and CDK4 [118], whereas another study on two dogs found that one carried an NRAS mutation and one carried KRAS, TP53, and KIT mutations [130]. Here, PTEN is linked to melanoma.