IL6 and COVID-19: The changes in the neutrophil to lymphocyte ratio, the peak platelet to lymphocyte ratio, lactate dehydrogenase (LDH), C-reactive protein (CRP), and interleukin-6 (IL-6) are considered to be associated with the progression and prognosis of COVID-19 [9], but using the information from the CLIs to give clinicians correct guidance is still a great challenge.