HTR2B and osteosarcoma: HTR2B belongs to the serotonin receptor family, and participates in tumor progression.[27] A previous study has shown that HTR2B is downregulated in aggressive breast cancer types, correlating with poor overall survival.[20] In colitis‐associated cancer, HTR2B knockout mice exhibited increased colitis and tumor severity, supporting its role as a potential tumor suppressor.[14] These studies align with our study, which demonstrates that HTR2B activation can suppress osteosarcoma progression.