Cities such as Paris, London, San Francisco, and Sydney provide "proof of concept" that combined prevention works and could eliminate HIV. This is certainly cause for celebration. A decline in the number of new diagnoses among men who have sex with men (the group most affected by HIV) has been observed in these cities in recent years. Against a backdrop of a sharp increase in HIV testing, the decline in new diagnoses reflects a real decrease in transmission, as shown by modeling that indicates a reduction in HIV incidence. The combined prevention approach, including “Test and Treat” and PrEP programs, is the strategy for success. Will our efforts be sustained enough to eliminate HIV?