Secretory phospholipase A2 (sPLA2) is the most studied, aberrant expression of human group IIA (hGIIA), III (hGIII) and X (hGX) sPLA2s has been associated with the pathology of colorectal, breast, gastric, oesophageal, ovarian and prostate cancers, which provide the potential for phospholipase to be designed as a stimulator in releasing drugs responsively.155,156 In addition, hyaluronidase, γ-Glutamyltranspeptidase, prostate-specific antigen, Trysin, β-galactosidase, Azoreductase, etc. are also used in enzyme-stimulated response smart nano-delivery systems.157–162. The gene discussed is PLA2G2D; the disease is prostate cancer.