The mRNA levels of IL-15 and its receptor (IL-15R) in the luminal secretory epithelium of BPH samples increased, as mentioned above, which may be due to the paracrine effect of IFN-γ, resulting in a twofold increase in IL-15 produced by stromal cells and lymphocyte activation and recruitment [53]. Here, IL15 is linked to benign prostatic hyperplasia.