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). Here, ICAM1 is linked to rheumatoid arthritis.