 The "PilS" gene is an example of this ability to rearrange as its combination with the "PilE" gene is estimated to produce over 100 variants of "the" PilE protein.These changes allow for adjustment to the differences in the local environment at the site of infection, evasion of recognition by targeted antibodies, and contribute to the lack of an effective vaccine.In addition to the ability to rearrange the genes it already has, it is also naturally competent to acquire new DNA (via plasmids), via its type IV pilus, specifically proteins Pil Q and Pil T. These processes allow "N. gonorrhoeae" to acquire/spread new genes, disguise itself with different surface proteins, and prevent the development of immunological memory – an ability which has led to antibiotic resistance and has also impeded vaccine development.