A scRNA-seq study on paired early-stage lung adenocarcinoma and non-cancerous lung tissue identified a tumor-enriched TAM population preferentially expressing high level of PPARγ, TREM, CD81, MARCO, and APOE, and was negatively associated with clinical outcome, suggesting a pro-tumor role is this TAM population (Lavin et al., 2017). Here, APOE is linked to neoplasm.