MUC1 and COVID-19: Xiuqu W. et al. showed elevations of serum cancer biomarkers in COVID-19 patients: squamous cell carcinoma antigens (SCC) and CA19.9 only in critical cases, carcinoembryonic antigen (CEA), carbohydrate antigens (CA-125, CA-153), cytocheretin-19 fragment (CYFRA21-1), HE4 in mild, severe and critical cases and concluded that elevations of these biomarkers is correlated with the pathological progressions of COVID-19 [40].