SR1 is a small-molecule AhR antagonist originally developed to enhance the self-renewal capacity of human hematopoietic stem cells by inhibiting AhR-mediated differentiation, and due to its relatively high affinity for AhR, SR1 has since been studied in broader contexts, including cancer metastasis, immune modulation, and barrier restoration in epithelial tissues [44]. Here, AHR is linked to cancer.