IL6 and lymphopenia: In particular, the cardinal laboratory features with prognostic potential are as follows: lymphopenia, either isolated or in parallel with an increased absolute neutrophil count; elevated concentrations of C-reactive protein (CRP), interleukin (IL)-6 and IL-2R; and increased levels of lactate dehydrogenase (LDH), D-dimer, ferritin, hepatic function markers and troponins [156,157,158].