MPO and cardiovascular disorder: Because transcriptomic analysis suggested an increase of transcripts for genes involved in neutrophil activation and signaling in PKM2−/− hearts after MI, such as S100a8, S100a9, and Il17ra (Figure 3d–f), we also co‐stained for myeloperoxidase which is predominantly expressed by neutrophils and has been shown to worsen tissue damage during inflammation and promote cardiovascular disease (Nicholls & Hazen, 2005).