Because the locations and patterns of NOTCH1 mutations in HNSCC and T cell acute lymphoblastic leukemia (T-ALL) were distinct, we pooled data available from genomic studies in the Catalogue Of Somatic Mutations In Cancer (COSMIC) database and The Cancer Genome Atlas (TCGA) Pan-Cancer Analysis of Whole Genomes Consortium in order to compare the structure of NOTCH1 mutations in T-ALL and HNSCC patients. The gene discussed is NOTCH1; the disease is cancer.