Study conducted on patients with adult T‐ALL treated on the United Kingdom Acute Lymphoblastic Leukaemia XII (UKALLXII)/Eastern Cooperative Oncology Group (ECOG), E2993 protocol found a notable positive correlation between a NOTCH1 mutation in the HD domain only and an FBXW7 mutation, and a strong negative correlation between NOTCH1‐PEST mutation and FBXW7 mutation. Here, NOTCH1 is linked to acute lymphoblastic leukemia.