TNF and rheumatoid arthritis: Moreover, Rotondo et al. suggested that pharmacologic immunosuppressive therapies such as anti-TNF could modify the immune response to Merkel cell Polyomavirus (MCPyV), thus undermining the outcome for positive MCPyV RA patients and increasing the probability of Merkel cell carcinomas (MCC) development, a rare but aggressive neuroendocrine tumor [55].