In prostate cancer, a study showed that the presence of CD4+ T cells in the tumor site promotes chemotherapy resistance (specifically to Enzalutamide and Doxorubicin) through the C-C motif chemokine ligand 5 (CCL5) signaling pathway (82), known to activate the Signal transducer and activator of transcription 3 (STAT3). This evidence concerns the gene CCL5 and prostate cancer.