Using RNAi to determine the dependency on individual anti-apoptotic BCL-2 members for survival, we have classified SCLC cell lines into BCL-2-addicted, BCL-XL-addicted, MCL-1-addicted or non-addicted to any single anti-apoptotic BCL-2 member. The gene discussed is BCL2L1; the disease is small cell lung carcinoma.