PKM and viral myocarditis: Additionally, the lncRNA AK083884 in M2-Exos interacts with macrophage pyruvate kinase M2 (PKM2), inhibiting its binding to HIF-1α and thereby promoting macrophage metabolic reprogramming and M2 polarization, ultimately improving the symptoms of viral myocarditis (Zhang Y. et al., 2024) (Table 1).