RAC2 and melanoma: The hotspot 35 is also shared by other Rho subfamily members: RAC2, RHOT1, RHOC. Even though one single mutation was found for each gene in our dataset, this position is extremely well conserved (a proline is present in all four genes) and all the mutations were found in melanoma patients without a RAC1 P29 mutation (Additional file 2: Table S5).