SUMO2 and gastric cancer: NSUN2 has been shown to promote the proliferation of gastric cancer cells by inhibiting cyclin-dependent kinase inhibitor 1C (p57Kip2) or interacting with small ubiquitin-like modifier (SUMO)-2/3,39,40 and has been implicated in breast, cervical, gallbladder, esophageal squamous cell, and uveal melanoma cancers,41–45 as well as being related to worse prognosis in pancreatic cancer and squamous carcinoma of the head and neck.46,47 However, NOP2 has not been extensively studied in tumors.