Of the six TMEM protein family genes comprised in our signature, the expression level of TMEM9B was lower in the high-risk group than that in the low-risk group and a lower expression of TMEM9B predicted worse overall survival in patients with osteosarcoma, suggesting that TMEM9B might act as a protective factor in osteosarcoma. The gene discussed is TMEM9B; the disease is osteosarcoma.