BCL2L1 and to a lesser extent also MCL1 are classified as common essential genes (mean Chronos Gene Dependency Scores −1.11 and −0.673, respectively), with only some cancer types being unaffected by deletion of either BCL2L1 or MCL1. In line with its frequent amplification in colorectal malignancies, deletion of BCL2L1 is highly lethal in colorectal cancer. The gene discussed is BCL2L1; the disease is cancer.