A 72-year-old woman presented with anemia (Hb 91 g/L), thrombocytosis (Platelets 502×109/L), and 10% bone marrow ring sideroblasts, fulfilling 2022 WHO diagnostic criteria through molecular precedence of SF3B1 p.K700E (VAF 40.5%) despite subthreshold sideroblasts. The gene discussed is GSTM1; the disease is Thrombocytosis.