CAT and cancer: The same plasma source and PAM have been already successfully tested in vitro to induce apoptosis in several cancer cell lines and the key possible mechanisms responsible for the plasma and PAM selectivity have been identified, especially the role of secondary 1O2 emerging from the mutual chemistry of H2O2 and NO2− in PAM, and inactivating the protective catalase on the cancer cell membranes [9,28,29].