For so long, the health care industry has been talking about the "threat of Amazon." Well, in 2018, those threats started to materialize, beginning with the announcement of a new venture that would target health care costs, and, most recently, digging into the electronic health record market. Whether embarking on new ventures with other companies or doubling down on its own initiatives, it's been a busy year for the retail giant (and we haven't even touched the headlines regarding the company's new dual-headquarters!) Take a look at the slideshow above for some key headlines from Amazon's eventful 2018. How is the health care industry responding to Amazon's entrance?