Cancer-related genes are targeted and dysregulated, causing expansions. (A) Frequently targeted genes. Gene name size corresponds to frequency with which the gene’s transcription start site was the nearest transcription start site to an integration site. Gene names in red are associated with human or murine leukemias.^38,39  (B) Integration clusters near MECOM among all patients. ISs in the sense and antisense orientation relative to MECOM are denoted by arrows. (C) A lower proportion of ISs was near the MECOM CIS region defined in the present analysis than in a retroviral WAS trial. The proportion of total integrations within the MECOM CIS area called by the kernel convolution approach was quantified for data sets from other clinical gene therapy trials. A Fisher exact test was used to compare the proportions, and P values are indicated. Error bars represent Gaussian approximation of a binomial 95% confidence interval.