In recent years, it has been demonstrated that L-733,060 displays antitumor activity against a large variety of cancer cell lines, including human SKN-BE(2) neuroblastoma, GAMG glioma, COLO 679, COLO 858, and MEL HO melanoma, WERI-Rb-1 and Y-79 retinoblastoma, and CAPAN-1 and PA-TU 8902 pancreatic, HEp-2 larynx, 23132/87 gastric, and SW-403 colon carcinoma cell lines and T-ALL BE-13 and B-ALL SD-1 leukemia cell lines [18, 20, 21, 23–25, 127] (see Figure 3). This evidence concerns the gene RB1 and acute lymphoblastic leukemia.