According to the article --
...influence can take many forms. When it comes to biomedical science policy in the US, the names of some people with clout are obvious. But beyond the Nobel laureates and university presidents there is another set of people who wield power. Some of these influential players, such as patient advocates or experts who churn out reports for think tanks, are well known within their own communities. Others, such as Senate staffers or policy makers at the US National Institutes of Health (NIH), operate under the radar.