CDKN2A and acute lymphoblastic leukemia: In addition, the genomic landscape of T‐ALL often includes “type B” mutations such as activating NOTCH1‐pathway mutations, deletions of CDKN2A, activation of the IL7R/JAK‐STAT pathway, and loss of the PTEN tumor suppressor gene (Van Vlierberghe et al, 2008; Girardi et al, 2017).