These ‘chemical parsing' experiments45 demonstrated that sensitization of BCL2High NHL cell lines to navitoclax in response to direct MCL-1 inhibition with A-1210477 or indirectly through loss in MCL-1 expression mediated by flavopiridol, is driven by BCL-2 inhibition with no contribution from BCL-XL. The gene discussed is BCL2L1; the disease is non-Hodgkin lymphoma.