Enhancer of zeste homolog 2 (EZH2) is involved in cisplatin (cDDP)‐induced proteasomal copper transporter 1 (CTR1) degradation. A, Western blot analysis for EZH2 and CTR1 in A2780ShNC, A2780ShEZH2, ES2ShNC, and ES2ShEZH2 cells treated with 20 μmol/L cycloheximide (CHX) for 3, 6, or 9 h and for the time course‐incurred decrease in CTR1. B, Western blot analysis for EZH2 and CTR1 in A2780ShNC, A2780ShEZH2, ES2ShNC, and ES2ShEZH2 cells treated with 20 μmol/L CHX to block protein synthesis and then exposed to 30 μmol/L cDDP for 3, 6, or 9 h and the time course‐incurred decrease in CTR1. C, Endogenous CTR1 immunoprecipitated from A2780ShNC, A2780ShEZH2, ES2ShNC, and ES2ShEZH2 cells treated with MG132, an inhibitor of the proteasomal degradation pathway, for 4 h and then treated with 30 μmol/L cDDP for 12 h. Western blot (WB) analysis of the mono‐ubiquitination (MonoUb) and poly‐ubiquitination (PolyUb) level of CTR1 in the immunoprecipitates