Lu R, Zhao X, Li J, et al. - Given that cases with viral pneumonia caused by an unidentified microbial agent were reported in late December 2019, in Wuhan, China, and the causative pathogen identified is a new coronavirus, provisionally named 2019 novel coronavirus (2019-nCoV), and more than 2,000 cases of 2019-nCoV infection have been corroborated as of Jan 26, 2020, and most of these included individuals residing in or visiting Wuhan, and human-to-human transmission has been verified, so, considering this background, researchers obtained complete and partial 2019-nCoV genome sequences from 9 inpatients, 8 of whom had visited the Huanan seafood market in Wuhan. They assessed the evolutionary history of the virus as well as focused on its likely origin, via a phylogenetic study of these 2019-nCoV genomes and those of other coronaviruses. They noted the extreme similarity in the 10 genome sequences of 2019-nCoV taken from the 9 patients, these showed more than 99·98% sequence identity. They also identified that 2019-nCoV was intimately associated (with 88% identity) with two bat-derived severe acute respiratory syndrome (SARS)-like coronaviruses, bat-SL-CoVZC45 and bat-SL-CoVZXC21, obtained in 2018 in Zhoushan, eastern China, but were more distant from SARS-CoV (nearly 79%) and Middle East respiratory syndrome-CoV (nearly 50%). Overall, 2019-nCoV was adequately divergent from SARS-CoV to be regarded as a novel human-infecting betacoronavirus. Bats were suggested to be possibly the original host of this virus, in phylogenetic analysis, but an animal sold at the seafood market in Wuhan might be an intermediate host promoting the emergence of the virus in humans. The possible ability of 2019-nCoV to bind to the angiotensin-converting enzyme 2 receptor in humans was also suggested in the structural analysis.