In an update on the status of Fantastic Voyage, a movie James Cameron is producing, he notes this in a Deadline article:

The original story, about a group of scientists who are reduced to microscopic size inside a submarine and injected into the body of an ill colleague, is taking on a new dimension in the version now in active development at 20th Century Fox. As first reported by Deadline, Cameron, busy with two sequels to Avatar among other projects, does not plan to direct — Shawn Levy (Real Steel) is attached as the helmer. “I gave him my idea about how this should be turned into a love story and he’s really run with it,” says Cameron, who noted that the script (originally written by Shane Salerno) with its complex premise has to be just right before it can get to the production level.

—-

Much like Titanic the new Voyage has a real emotional core to it, basically dealing with a doctor going through troubled times in his marriage who finds himself injected into his gravely ill wife in order to save her life.

Cameron has long claimed that Titanic was at its core a love story. Or at least that’s how he approached the venture. It’s great to have a story with huge scope and stakes, but writers have to provide points of emotional connection for the reader in order for them to become invested in that bigger story.

For more of the Deadline article, go here.