M2 macrophages were associated with increased microvessel density in pancreatic ductal adenocarcinoma (PDAC) tissues, and exosomal miR-155-5p and miR-211-5p derived from M2 macrophages targeted E2F transcription factor 2 (E2F2) and promoted the angiogenic functions of mouse aortic ECs in vitro (Yang et al., 2021). Here, E2F2 is linked to pancreatic ductal adenocarcinoma.