The clinical diagnosis despite negative PCR and anti-SARS-CoV-2 antibodies was based on clinical features: they required admission for typical COVID-19 clinical, radiological (unilateral or bilateral pneumonia) and analytical features (very low lymphocyte counts, higher D-dimer values than other hemodialysis non-affected patients and high IL-6 levels) (Table S1). This evidence concerns the gene IL6 and pneumonia.