There were two cases of myeloid sarcoma (Table 5), of which case 522 was a myeloid sarcoma (monoblastic variant) occurring in the skin of a 3-month-old girl, and case 630 a myeloid sarcoma in the orbit of a 5-year-old boy, which was followed by an AML with t(8;20;21)(q22;q11.2;q22.1); RUNX1::RUNXT1. The gene discussed is RUNX1; the disease is myeloid sarcoma.