While a previous study stated that decreased lumbar muscle density is predictive of inferior PFS in patients with metastatic melanoma treated with ipilimumab,25 several other studies conducted in patients with metastatic NSCLC treated with PD‐1/PD‐L1 inhibitors were skeptical about its predictive value.10, 17. The gene discussed is PDCD1; the disease is metastatic melanoma.