NOTCH1 mutations, immunohistochemical staining for activated NOTCH1, and HES4 expression are biomarkers that can be used to identify solid tumors that are likely to respond to GSI-based therapies.
Finally, the identification of NOTCH1 mutations in solid tumors and chronic lymphocytic leukemias has increased even further the clinical relevance of NOTCH signaling as a therapeutic target in human cancer.
Although its role in T-ALL is well characterized and further supported by a high frequency of activating NOTCH1 mutations in T-ALL patients, it still remains an open question whether the effects of Notch signaling are causative in other types of cancer, including solid tumors.