ADRB2 and colorectal carcinoma: We detected the mRNA levels of 9 ARs in CRC cell lines, including HT-29, SW480, LoVo, MC38 and CT26, and human colon mucosal epithelial cell lines NCM460, consistent with the report that β2-adreneric receptor (β2-AR) is the major mediator for chronic stress mediated cancer development 33, we observed that β2-AR (ADRB2) is the dominant expressing ARs in these CRC cells (Figure 4A and S3A).