Table 1.

Oncogenic events leading to aberrant NOTCH1 signaling in T-ALL

Mutation	Mechanism of action	Prevalence in T-ALL
t(7;9)(q34;q34) t(9;14)(q34.3;q11.2)	NOTCH1 truncation and translocation to the TCR locus. Overexpression and ligand independent activation	1%
NOTCH1 HD class I	Ligand hypersensitivity or independent activation	40–45%
NOTCH1 HD class II	Ligand hypersensitivity or independent activation	1%
NOTCH1 JME	Ligand hypersensitivity or independent activation	3%
NOTCH1 ΔPEST	Increased activated NOTCH1 protein stability	10–20%
FBXW7 mutations	Increased NOTCH1, c-MYC, Cyclin E, JUN and mTOR protein stability	15%