COPS5 and hepatocellular carcinoma: Similar results were obtained by shRNA‐mediated COPS5 knockdown (KD) in the parental HCC cell line SNU449 and the sorafenib‐resistant cell subline HUH‐7R (Figure 2A,B,D; Figure S3C–E, Supporting Information), which were derived from the HCC cell line HUH‐7 by continuous selection with sorafenib.