DOT1L and influenza: A549 cells were plated alone or with Dot1L inhibitor (48 h), then infected at low m.o.i. with the PR8hv strain, with another laboratory-passaged influenza strain, A/WSN/33 (WSN) (Fig. 2A) or with one of two natural 2009 pandemic isolates, A/California/04/2009 (CAL04) and A/California/07/2009 (CAL07) (Fig. 2B) and analyzed production of infectious particles in each condition.