Evidence supporting this hypothesis includes associations of lung cancer with 1) elevated inflammatory markers, such as C-reactive protein, interleukin (IL)-6, and IL-8 [5], [6]; 2) chronic obstructive pulmonary disease, to which infections can contribute [7], [8]; 3) human leukocyte antigen polymorphisms in genome-wide association studies [9], [10]; and 4) overt infections like tuberculosis and pneumonia [3], [7]. This evidence concerns the gene IL6 and infection.