The apparent increase of 292K in the 2 most recent years coincided with the detection globally of a new 3C H3N2 clade.28 Whether HA or NA mutations of the new clade 3C viruses that emerged during the 2011 influenza season relative to earlier Influenza A H3N2 clades increase the replicative capacity of R292K containing viruses similar to V241I/N369K in 2009pdmH1N1 for H275Y remains to be investigated. This evidence concerns the gene XK and influenza.