 Green t-catechin EGCG has been studied for its health benefits as a nutraceutical agent, but it can also act as a pro-oxidant in certain cellular contexts. Recent research reveals that EGCG directly interacts with proteins and phospholipids in the plasma membrane to regulate signal-transduction pathways, transcription factors, DNA methylation, mitochondrial function, and autophagy, leading to its beneficial biological actions. This article was authored by Hasak Kim, Michael J. Kwan, and John A. Kim.