IL6 and COVID-19: For example, several hematological parameters, such as the neutrophil count (Neu#), monocyte count (Mon#), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and systemic immune-inflammation index (SII), are positively associated with COVID-19 (13–15), along with the levels of several biochemical parameters and cytokines, such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), C-reactive protein (CRP), and interleukin 6 (IL-6) (16, 17).