Fig. 4From: Identification of combinatorial host-specific signatures with a potential to affect host adaptation in influenza A H1N1 and H3N2 subtypesPhylogenetic tree of the M1 protein from sequences of both subtypes and both hosts. Both the subtypes and the hosts are combined into a single tree. It can be seen that human sequences of both the subtypes form their own distinct clades. The avian sequences, on the other hand, fell into a single cladeBack to article page