Our study results showed that non-severe COVID-19 patients had lower risk of thrombosis development in line with a meta-analysis which supported the relation between COVID-19 severity along with changes in primary and secondary haemostatic parameters characterised by longer prothrombin time (PT), higher D-dimer values, and lower platelet count (Di Minno et al., 2020). This evidence concerns the gene F2 and COVID-19.