IL6 and COVID-19: As an example, MR studies have demonstrated that genetic mimicry of interleukin-6 receptor blockade (targeted by tocilizumab) is associated with lower risk of rheumatoid arthritis109,110 but also with reduced risks of several CVDs110–115 as well as COVID-19.116 Nonetheless, a possible side effect is an increased risk of pneumonia.110,116 These findings suggest that blockade of the interleukin-6 signalling pathway may be a target for the prevention of diverse CVDs and COVID-19 but that caution should be taken with regard to possible adverse effects.