Cardiac toxicities, of interest in the context of BTK inhibitors, were uncommon, with one case each of angina pectoris (grade 3), cardiac failure (grade 2), cardiovascular disorder (grade 1), mitral valve insufficiency (grade 2) and sinus bradycardia (grade 1); no atrial fibrillation episodes were reported. The gene discussed is BTK; the disease is Sinus bradycardia.