H1-2 and diffuse large B-cell lymphoma: Along with other genes (HIST1H1C/D/E, and SMARCA4), the ARD1A gene, one of the regulators of higher-order chromatin structure, has been reported to be mutated in ⩾5% of DLBCL or follicular lymphoma [42]. In our study, a much higher yield of 12.9% was seen, with ARID1A in all subtypes.