Comparison to the Enterovirus species criteria revealed several features that may also be applicable for classifying HRV A2 strains. Firstly, although we could not identify a specific receptor using these in silico methods, the HRV-QPM models most closely accommodated interaction with an ICAM-1-like molecule, similar to some HEV C viruses [44] . Secondly, HRV A2 genomes exhibited #2.5% variation in G+C composition compared to HEV C and HEV D and ,5% compared to HEV A and HEV B. Thirdly, HRV-and HEV-like protease cleavage sites and locations suggested similar proteolytic processing ( Figure 1A ). Although we have been unable to find any indication of recombination in HRV-QPM [31] , the differences in amino acid identity within the novel HRVs, particularly in the 2C and 3CD region of HRV-X2, -C024 and -C025 compared to HRV-QPM, -X1 and -C026 (data not shown), may indicate a relevant event requiring further study. In sum, these data indicate that the HRV A2 strains cannot be assigned to an existing HRV or HEV species and should be assigned to a new species, tentatively called Human rhinovirus C.