The role of the tSH3s within the larger family members, TKS4 and TKS5 is much less understood [21,26,27,95], although both of them are heavily implicated in diseases, most importantly in the metastatic potential of different cancers, such as melanoma, lung cancer and colon cancer, among others [57,59,60,78,95,96,97]. This evidence concerns the gene SH3PXD2A and melanoma.