The Moon could be the starting point for Mars colonization. Also, it would make a huge difference if the new Moon missions took advantage of the ISS, which the Apollo missions couldn't count on. One thing is bringing all crew, supplies and equipment from Earth in one trip, and a whole different thing is sending everything on/around the ISS using unmanned cargo missions, then assemble the lunar mission ships up there and send the Moon astronauts when necessary. In other words: Earth<->ISS, then ISS<->Moon<->Mars and/or ISS<->Mars.