As Muppala et al [59] recently reported on Src mediated miR-21 expression in colorectal cancer cells and it is well-known that IL-2 activates Src kinases such as Lck, we speculate that Src kinases migh also be involved in IL-2 and IL-15-mediated miR-21 expression. The gene discussed is IL15; the disease is colorectal cancer.