S Marks the Spot: Linking the Antioxidant Activity of N-Acetyl Cysteine to H 2 S and Sulfane Sulfur Species.

N-Acetyl cysteine (NAC) is commonly used as an antioxidant and cytoprotectant, yet a broadly applicable mechanism of these activities has remained elusive. In this issue of Cell Chemical Biology, Ezeriņa et al. (2018) report an alternative mechanism for NAC cytoprotection and antioxidant activity by demonstrating that NAC treatment increases sulfane sulfur production via intermediate H2 S generation.