In addition, we recently observed that overexpression of RBM5 induced expression of KRAS in the A549 lung cancer cell line and decreased expression of KRAS in the MCF-7 breast cancer cell line [Wang et al, unpublished data], suggesting that RBM5 functions upstream of KRAS, albeit with different outcomes, depending on tissue of origin. The gene discussed is KRAS; the disease is lung carcinoma.