The identified TYROBP→TREM2→A2M→APOE→APOC1 cascade is supported by the reports that TREM2 is expressed in tumor macrophages in over 200 human cancer cases (Molgora et al., 2020) and that there are interactions between TREM2/A2M, TREM2/APOE, A2M/APOE, and APOE/APOC1 (Krasemann et al., 2017). Here, APOE is linked to cancer.