IL6 and chronic kidney disease: As summarized in Fig. 3 and Supplementary Table S6, beyond older age, male sex, and presence of CKD, the following risk factors at admission were identified: a worst respiratory function (lower SpO2, P/F), higher neutrophil count, higher inflammatory markers (CRP, IL-6, fibrinogen), presence of liver-pancreatic-muscle damage (higher AST, bilirubin, amylases, LDH, CPK) and hematuria.