USP7 and gastric cancer: More specifically, the dysregulation of USP7 expression has been linked to the onset of many malignancies, such as multiple myeloma [58], prostate cancer [16], ovarian cancer [59], cervical cancer [60], glioma [61], colorectal cancer (CRC) [19], liver and brain cancer [9], gastric cancer [2], and head and neck cancer [62].