RASA1 and cancer: However, although protein modulation of RasGAP has been found in several neoplasms including chronic myelogenous leukemia [17], astrocytoma [18], trophoblastic tumors [19], prostate cancer [20], liver cancer [21], and basal cell carcinoma [22], protein levels have not necessarily been found to be correlated with RAS activity or cancer severity [22], [23].