NOTCH1 peptides that are similar to the membrane-bound furin-processed forms ΔEGFΔLNR or NICD1 are insensitive to thapsigargin inhibition, and they properly localize to the cell surface, suggesting that the Ca2+-ATPase activity is required for the furin-mediated cleavage of NOTCH1 precursors in T-ALL cells [35]. Here, FURIN is linked to acute lymphoblastic leukemia.