Another MoMuLV screen to identify genes that can substitute for Pim1 and Pim2 in lymphomagenesis in Myc transgenic, Pim1, and Pim2 doubly deficient mice [71], uncovered several CIS (of which 10 belonged to the Pim complementation group), which furthered our understanding of Pim1/2-driven lymphomagenesis. Here, PIM1 is linked to in situ carcinoma.