Given their prevalence in a large number of cancers,83 together with evidence implicating mutations, such as Rac1 P29S in conferring resistance against B-Raf proto-oncogene, serine/threonine kinase (BRAF) inhibitors in melanoma,84 Rac1 activating mutants, similarly to Rac1b, represent attractive anti-cancer therapeutic targets. This evidence concerns the gene RAC1 and cancer.