RB1 and osteosarcoma: PGPVs in disease‐specific genes such as RB1 (loss: 1 patient, truncating variant: 1 patient), NF1 (truncating variant: 4 patients, missense: 1 patient), TP53 (truncating variant: 1 patient), and SDHA (missense: 1 patient) were identified in two osteosarcoma cases, one undifferentiated sarcoma case, and three malignant peripheral nerve sheath tumor cases.