RAC1 and hepatocellular carcinoma: As shown in Figure 5E, DOCK8 or Rac1 was then found to co-immunoprecipitate with each other in 7721 and Huh-7 cell lysates, indicating that DOCK8 can physically interact with Rac1 and DOCK8 is very likely to be a GEF for Rac1 in HCC cells.