TNF and psoriatic arthritis: The regulation of the TNFR1 signalling pathway by TNF-α is considered clinically significant because failure to modulate this mechanism could lead to serious diseases, such as inflammatory bowel diseases, rheumatoid arthritis, psoriatic arthritis, psoriasis, juvenile idiopathic arthritis, ankylosing spondylitis, Crohn’s disease, degenerative diseases and ulcerative colitis [3, 48].