BTK and cancer: An in vitro study by Chen et al. demonstrated that BTK C481S, i.e. the most common BTK mutation in WM patients, results in sustained ERK1/2-mediated survival signaling and ibrutinib resistance in MYD88-mutated WM and large B-cell lymphoma cells and confers protection against ibrutinib to neighboring BTK wild-type cancer cells through cytokine release (67).