CD109 and neoplasm: In tumor cells, CD109 expression was reported to regulate epidermal growth factor receptor (EGFR) and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathways [10,11], and CD109 decreased sensitivity to EGFR-tyrosine kinase inhibitor (TKI) therapy in lung adenocarcinoma cells [12].