CCL21 and neoplasm: Inhibition of CCR7 (the receptor for CCL21) and CXCR4 (the receptor for CXCL12), respectively, released DC and CD8T cells from TNC, thus identifying ‘TIL-matrix retention’ as a novel mechanism for how TNC impairs anti-tumor immune surveillance, and also provided an explanation for the immune exclusion phenotype where TILs are found to be trapped in the stroma, an indicator of poor efficacy of immune checkpoint therapy (Petitprez et al., 2020; Pagès et al., 2018).