SAG and neoplasm: Finally, given that Sag is pro-oncogenic in the lung [25] and tumor-suppressive in the skin [29] during KrasG12D-induced tumorigenesis, and pro-oncogenic in the prostate during tumorigenesis induced by Pten loss (this study), Sag appears to be a conditional pro-oncogenic or tumor suppressive co-operating gene in tissue- and context-dependent manner.