CD4 and lung cancer: IHC review of the biopsy samples from the left lung and pelvic tumor at the time of diagnosis showed that there were few TILs including CD8+ T cells (NCL‐L‐CD8‐4B11, Leica Microsystems), CD4+ T cells (NCL‐L‐CD4‐1F6, Leica Microsystems), and PD‐1+ cells (NAT105, Abcam) in both biopsy samples obtained from the primary lung cancer site and metastatic site of the left pelvis (Figure 4(a)–(h)).