VAV1 and lung cancer: Our results clearly show an association between the presence of c-Myb and vav1 expression since over-expression of c-Myb in Vav1-negative H460 lung cancer cells along with the vav1 reporter gene induced expression of luciferase (Fig. 5B), while depletion of c-myb expression in Vav1-positive H441 lung cancer cells led to a marked reduction in vav1 mRNA expression (Fig. 5C).