Compared to the rest of our cohort, patients with lung cancer had a similar age (both with a median age of 57 years, p = 0.705), a lower median CD4 nadir count (71 [95% CI 43–105] vs. 179 [95% CI 80–309] cells/uL), lower current CD4 count (352 [95% CI 242–517] vs. 672 [95% CI 430–921] cells/uL), and a higher median pack-year (71 [95% CI 50–91] vs. 32 [95% CI 35–40]). Here, CD4 is linked to lung cancer.