RAC1 and lung cancer: When Rac1 is activated it participates in the formation of actin stress fibers and adhesion plaques, promotes cytoskeleton reorganization, regulates sheet pseudopodia and filopodia extension, affects the structure and polarization of the cell, promotes cell motility and migration and inhibits apoptosis.10 Studies in recent years have shown that Rac1 expression in colon, breast and lung cancer, among others, was significantly increased.