VAV1 and lung carcinoma: Third, we found differential expression of c-myb RNA in cell lines of different histological origins: it was present at very high levels in Jurkat T cells, somewhat lower levels in H441 lung cancer cells, and not at all in the H460 lung cancer cell line (Fig. 5A), suggesting that expression of c-Myb and Vav1 may be correlated in these cells.