In ARID2 and ARID1B, most cancer-associated variants are somatic and null variants, and only few germline variants or copy number variations are reported to be associated with cancers, such as the ARID2 variant c.4634A>G, p.Asn1545Ser identified in an acute lymphoblastic leukaemia case and the 6q25 deletion (including ARID1B) in papillary thyroid cancer (Sausen et al., 2013; Vengoechea et al., 2014; de Smith et al., 2019; Wang et al., 2021). The gene discussed is ARID2; the disease is acute lymphoblastic leukemia.