Three different subsets of neuroblastomas with different BCL-2 family proteins’ dependency were identified: Those that were (1) high in MCL-1 expression (reacted with NOXA-BH3 peptides and are sensitive to killing by MCL-1 inhibitor AT-101 and not ABT-737), (2) high in both/either BCL-XL or BCL-w expression (reacted with BIK-BH3 peptides and are sensitive to killing by ABT-737), and (3) relapsed cases, which are insensitive to both BH3 peptides and inhibitors [72]. The gene discussed is MCL1; the disease is neuroblastoma.