Intratumoral microbiota enhanced the secretion of specific chemokines (e.g., C-C motif chemokine ligand 2 (CCL2), CCL4, CXCL1 and CXCL10) and interleukins (e.g., IL-1β, IL-6 and IL-10) into the surrounding milieu, leading to T cell exclusion and tumor growth. This evidence concerns the gene CCL2 and neoplasm.