NOTCH1 and precursor B-cell acute lymphoblastic leukemia: However, studies have shown that NOTCH signaling receptors are also present on the surface of B cells (35), and NOTCH signaling has been implicated in B-ALL resistance (36).In our study, NOTCH1mutations were detected in 9.8% of B-ALL cases, and all 4 NOTCH1+ B-ALL cases were in the high-risk group, suggesting that NOTCH1 mutations may be associated with drug resistance and a poor prognosis in B-ALL.