CCL21 and neoplasm: In line with such phenotypic changes in melanoma tumor-draining LN FRCs, oxidative phosphorylation programs are upregulated in tumor-draining LN FRCs in a metastatic breast cancer model (Li et al., 2020), and an inverse regulation of FRC PDPN and CCL21 expressions are observed in murine and in vitro B cell lymphoma models (Apollonio et al., 2023).