IL6 and pulmonary fibrosis: For example, the IL8, C–X–C motif chemokine ligand 2 (CXCL2), CSF2, IL6, TNF and interleukin 1 beta (IL1B) genes were overlapped between the ‘lung fibrosis’ and ‘rheumatoid arthritis’ pathways, while the IL6, TNF, ICAM1, IL1B, and NFKB2 genes were common in the ‘vitamin B12 metabolism’ and ‘photodynamic therapy-induced NF-kB survival-signaling’ pathways (Figure 2B).