Most surprisingly, 20 of the 34 strains classified as HRV-C by comparative analysis of VP4/P2 sequences ( Table 2) were related more closely to HRV-A strains when their 59UTRs were analyzed, and showed incongruent clustering in phylogenetic trees (Figs. 1 and 2). The nucleotide sequences in the 59UTR of these strains were related closely to those of formerly identified QPM, NAT001, NAT045, C024, C025 and C026 HRV-C strains, and to some of the W strains recently identified as HRV-A [15] (Fig. 2) . However, our 20 strains clustered together with these six strains in two major branches in the phylogenetic tree constituted a subspecies of HRV-C called HRV-Ca (Table 3 , Figs. 2 and 3) . The fourteen other HRV-C strains formed another unique branch of HRV-C subspecies, called HRV-Cc, which clustered differently from other species of HRV-A and HRV-B, and from subspecies HRV-Ca in the phylogenetic tree based on 59UTR sequences (Table 3 ; Figs. 1 and 2). These strains were related closely to some W strains of HRV that were classified as HRV-C [15] (Fig. 2 , Table 3 )