Additionally, siRNA mediated knockdown of Tspan33 in HeLa cells reduced the γ-secretase dependent cleavage of a constitutively active, truncated form of Notch1 and that of T-cell acute lymphoblastic leukemia (T-ALL) Notch1 oncogenic mutants (Dunn et al., 2010). Here, NOTCH1 is linked to T-cell acute lymphoblastic leukemia.