GIT1 and neoplasm: To further assess whether the increased tumour growth observed in the GIT1 knockdown tumours was caused by an increase in Notch signalling, we used a dominant-negative mutant of Mastermind-like 1 (DNMM1), which inhibits the interaction between the Notch ICD and CSL and thus acts as a negative regulator of Notch signalling29,30.