Notch1 is processed by furin, which is a vital step in the maturation process and occurs at the S1 cleavage site in the Golgi apparatus (Figure 4b).1 To analyze the impact of CJ on this maturation step, protein extracts of CJ-treated T-ALL cell lines were immunoblotted to detect the Notch1 furin-processed transmembrane subunit (NTM, 120 kDa). Here, FURIN is linked to acute lymphoblastic leukemia.