Comutation plot for variants detected in primary tumor at study entry. (Left) Clustered according to best clinical response: CR Complete response, PR Partial response, SD Stable disease, PD Progressive disease. Unique sample identifier and MZL subtype also represented. Mutation burden is expressed relative to sample with highest number of mutations detected. Only one mutation per gene per tumor sample is represented. (Right) Ribbon diagram of BTK structure showing location of the non-catalytic E41K mutation distant from zanubrutinib binding site.