A compound targeting serotonin receptor 5-HT2A (5-HT2AR) signaling in the gut could activate antitumor immunity in colorectal cancer (CRC) and improve responses to immunotherapy without causing psychedelic effects in the brain. The activation of 5-HT2AR in enteric glial cells (EGCs) by this approach induces the production of the immune mediators C-X-C motif chemokine ligand 10 (CXCL10) and interleukin-18 (IL-18), which recruit CD8+ T cells into the tumor microenvironment and boost their ability