IL17A and bacterial infectious disease: Local inflammatory conditions of the testis, as well as systemic inflammation, have negative impacts on spermatogenesis for different reasons, such as bacterial infections and viral infections, which cause an invasion of monocyte‐derived macrophages, with increased production of pro‐inflammatory cytokines such as IL‐6, TNF‐α, IL‐17, IL‐1β and chemokines by resident testicular cells, resulting in a negative impact on spermatogenesis and steroidogenesis [35].