Specific candidate genes have been identified through studies analyzing families with multiple ET cases, such as FUS, TENM4, STK32B, LINGO1, SORT1, SCN4A, NOS3, KCNS2, HAPLN4/BRAL2, and USP46, with variants often unique to families from diverse ethnic backgrounds [6]. The gene discussed is HAPLN4; the disease is essential thrombocythemia.