Like A375 melanoma cells expressing Vav1 or Rac1 P29S, the BRAFi-resistance phenotype of VRPP1-3 cells was blunted by the group I PAK inhibitor G-5555 (Fig. 4), confirming that group I PAKs can also contribute to spontaneous Rac1-driven BRAFi resistance. Here, VAV1 is linked to melanoma.