Some years ago, The Bolt-on Bioreactor (BoB) project was launched with an objective of bringing to the market an efficient bioreactor for culturing adherent cells. The BoB team identified four challenges that needed be addressed to succeed: volumetric productivity, process automation, containment and sterility, and process economics. BPI published findings related to those challenges and proposals of the BoB team to solve them in a four-article series in 2015. Here, the author offers an update on developments in The Bolt-on…