As previously reported by Wang and Tsai, JAB1 is a proto‐oncogene that shows abnormal expression in a variety of human cancers and plays an essential role in the development and metastasis of cancers; a high level of JAB1 is often correlated with a poor prognosis.17, 18 Knockdown of JAB1 inhibits the proliferation of human tumor cells, suggesting that overexpression of JAB1 not only serves as a marker of malignant transformation, but also actually contributes to tumor cell proliferation. Here, COPS5 is linked to cancer.