For example, when used as second-line therapies in lung adenocarcinoma patients without selection on the basis of PD-L1 tumor expression, response rates above 20–25% are rarely achieved.100,102 Only a subgroup of colorectal cancer patients respond to PD-L1/PD-1 blockades.103 This complicates matters for the cancer patient because these therapies are currently very costly, and the demand for these treatments is increasing. The gene discussed is CD274; the disease is lung adenocarcinoma.