Copper(Cu)is a redox-active metal ion essential for most aerobic organisms.Cu serves as a catalytic and structural cofactor for enzymes that function in multiple biological processes.Defects of copper homeostasis are responsible for many diseases,such as tumor,immunity [1].Atox1 is one of the most important copper chaperones for maintaining cellular copper homeostasis and acts as a transcription factor to promote the expression of cytokines and key metal-proteases.It is important to study the interaction proteins and signal transduction of Atox1 in tumor cells.Protein C,a zinc finger protein closely related to tumor development,has been confirmed to interact with Atox1 captured by APEX2 proximity live labeling strategy[2].Protein C binds to copper with a high affinity and Atox1 can transport copper to protein C.Whats more,copper can bind to protein C competing with zinc,copper-bound protein C becomes unstable with functions losing,thus affects tumor cell destiny.