Analysis of the association between serotonin receptors (HTR1A, HTR1B, HTR1D, HTR1E, HTR1F, HTR2A, HTR2B, HTR2C, HTR4, HTR5A, HTR6, and HTR7) and osteosarcoma prognosis in the TARGET‐Osteosarcoma database revealed that low expression of HTR2B correlated with patient poor outcomes (Figure1A). The gene discussed is HTR1D; the disease is osteosarcoma.