Immunohistochemistry further showed that the tumors were positive for several putative OS markers, such as CD99 33, ALP 35, osteonectin 36, and osteocalcin 37 (Fig. 4B), and partially positive for sarcoma markers, such as desmin 38 and α‐SMA 38 (Fig. 4C). The gene discussed is CD99; the disease is sarcoma.