CISs and proto-oncogenes are overrepresented in RV integrations and integration hot spots. Comparative analysis of the frequency of genes annotated in the CIS and proto-oncogene databases (see “Materials and methods, Functional clustering analysis” for definitions and data source) between integration target and control gene lists. Bars represent the percentage of RV and LV integrations, RV and LV integration hot spots, and control sequences targeting at least 1 proto-oncogene or CIS. The n values indicate the number of independent hits in each group. Asterisks denote the level of enrichment with respect to control data set (2-sample test for equality of proportions with continuity correction; ***P < .001; *P < .05).