Cystic Fibrosis Step by Step: What is Cystic Fibrosis? Posted by Gunnar Esiason | Mar 7, 2017 | Podcast | In the Boomer Esiason Foundation’s new educational program, Cystic Fibrosis Step by Step with Gunnar Esiason, some of the BEF cystic fibrosis advocates explain what CF means to them…. outside the scientific definition.