PIWIL4 and infection: To examine transcriptomic changes in both small and long RNA, M2MC and nonM2MC cells were isolated from Miwi2+/tom and Miwi2tom/tom mice intratracheally instilled with saline or mouse-adapted influenza A/Puerto Rico/8/34 (PR8) 3 days post infection (dpi) (Figure 1C).50