IL6 and COVID-19: For example, coagulation factor deficiencies with tocilizumab, and peripheral embolism and thrombosis with sarilumab, are presumably related to the use of these anti-IL6 to treat the pro-coagulative cytokine storm, characteristic of severe COVID-19 (Kichloo et al., 2020; Xu et al., 2020), suggesting an indication bias.