As shown in Table 1, PAX5 deletions occurred in 15.9%–31.7% of pediatric Ph− B-ALL, 33% of pediatric Ph+ B-ALL (14), 27.1%–40% of adult Ph+ B-ALL, and 22.9%–23.8% of adult Ph-B-ALL (31.8%–38% Ph-like ALL) cases. Here, PAX5 is linked to acute lymphoblastic leukemia.