In the article, “Effect of optimized collagenase digestion on isolated and cultured nucleus pulposus cells in degenerated intervertebral discs”,[ which appeared in Volume 97, Issue 44 of Medicine, the authors would like to note funding from the below sources:1. The Program for Medical Key Department of Shanghai (no: ZK 2015B17);2. The Key Disciplines Group Construction Project of Pudong Health Bureau of Shanghai (no: PWZxq2017–11).