The levels of Interleukin 24 (IL-24), a cytokine that inhibits tumor progression, and its receptor, the IL-24 receptor (IL-24R), are found to be reduced in breast cancer samples and are associated with increased levels of lymph-specific markers, such as podoplanin, PROX1, and LYVE-1. The gene discussed is PDPN; the disease is breast carcinoma.