STAT3 and cancer: 2016). In particular, dimeric PKM2 was shown to translocate into the nucleus to activate STAT3 in CD4+T cells, macrophages, and cancer cells (Ma et al. 2019; Damasceno et al. 2020; Hou et al. 2020). However, the potential mechanisms of PKM2 in T cell activation and differentiation remain unclear. Recent studies reported that inducing PKM2 tetramerization and blocking its nuclear translocation could strongly inhibit CD4+T cell activation and pathogenicity (Angiari et al. 2020), and the expression of PKM2 is associated with Th17 cell differentiation (Seki et al. 2020).