Genetic analysis of novel coronavirus (2019-nCoV), severe acute respiratory syndrome (SARS) virus and human coronaviruses 229E, NL63, OC43 and HKU1. Phylogenetic analysis of the 2019-nCoV gene: (A) coronavirus phylogenetic tree and (B) phylogenetic tree of 746 strains of 2019-nCoV. Strains from different regions are shown in different colours. Those marked red are from China. (C) Histogram of similarity distributions between all the strain pairs. The minimum and maximum pair-wise similarities were 82.2% and 100%, respectively.