Retroviral insertions near the miR-29a/b and miR-106a~363 clusters. Retroviral insertions are found close to the miRNA gene cluster miR-29b-1/29a on mouse chromosome 6 (left) and the miR-106a~363 cluster on mouse chromosome X (right). CIS-1 retroviral integration sites are depicted with a box and the genetic background/virus model is numbered as follows: (1) p16−/−, (2) PDGFB_MMLV in C57BL/6, (3) AKV in AKxD, (4) Cas-Br-M in BALB/c, (5) AKV in Blm−/−, (6) AKV in Blm+/+, (7) MOL4070 in NUP98-HOXD13, (8) M-MuLV in C57BL6 p27−/−, (9) M-MuLV in NIH/Swiss, (10) M-MuLV in C57BL6 p27−/+, and (11) M-MuLV in 101 X C3H. CIS-2 retroviral integration sites are depicted with a circle and the genetic background/virus model is numbered as follows: (1) p19−/−, (2) wild-type FVB mice (3) p53−/−, (4) p15−/−, (5) p15−/− plus p21−/−, (6) p21−/− or p21−/+, (7) p27−/− or p27−/+, (8) p21−/− plus p27−/−, and (9) p16−/− plus p19−/−. The gray-shaded background depicts regions encompassing CIS-3 retroviral events. Multiple integration events from the same model system that are too close to be resolved in the figure will be shown as only a single hit.