ITPRIPL1 and neoplasm: Isogenic cell lines were engineered to overexpress either cyclin D1a (in Ccnd1+/+ MAFs +/+-D1a) or cyclin D1b (in Ccnd1KI/KI MAFs- KI/KI-D1b) (Fig3E), subcutaneously implanted into the flanks of nude mice, and monitored for tumor growth over a period of 1 year.