Proviral insertions are randomly distributed throughout the genome and define CISs. (A) Blue lines represent all the insertions recovered from the screen overlaid on the mouse chromosomes, labeled above. Red lines represent all the resulting CISs. (B-C) Two representative CISs with the distribution of insertions. (B) Insertions defining Fosb; (C) insertions defining Mn1. The red bars define a CIS region. The scale and chromosome region are above the CIS region while the insertions from the different mice in the screen are below. With respect to the primary CIS-associated genes, blue lines on the insertion track indicate positive orientation and green lines indicate a negative orientation. RefSeq genes within the CIS are in blue at the bottom of each figure.