CCL22 and colorectal carcinoma: CCL22, the dominant CCR4 ligand for Treg recruitment in tumors, has been described in different solid tumors (breast and cervical cancers, glioblastoma, squamous cell carcinoma (SCC), CRC and PDAC), where its expression correlates with Treg infiltrate and poor prognosis [22,25,31,46,66,67,68,69,70].