Tumor biomarkers. Established biomarkers of response to immune checkpoint blockade were examined in pretreatment tumors. (A): Stromal TILs were evaluated by pathologists at City of Hope (n = 13). (B): Tumor mutation burden, depicted as m/MB, was evaluated by the TEMPUS xT genome alteration panel (n = 14). Statistics were assessed by two‐tailed Mann‐Whitney test. For both graphs, the median is represented by a line. Nonresponders (progressive disease + stable disease) in red, responders (complete response + partial response) in blue.