Several additional studies confirmed the role of [18F]FDG to monitor response to immune checkpoint inhibition in patients with advanced melanoma treated with CTLA-4 inhibitors (132–134) and advanced NSCLC patients under PD-1 inhibition (124) These studies suggest that [18F]FDG may serve as a predictor of response of immune checkpoint inhibition (132, 133), as long as immune therapy related response patterns are taken into account, e.g. appearance of new lesions or initial limited increase in tumor burden not per se define progression (135, 136). The gene discussed is CTLA4; the disease is non-small cell lung carcinoma.