OTUD4 and neoplasm: In MERAV, the expressions of YOD1, OTUD4 and OTUD6b in tumor tissues and cell lines were different from those in normal tissues (Additional file 1: Fig. S1). In GEPIA, the expressions of OTUD1, YOD1, and OTUD5 were higher in tumor tissues than in normal tissues (P < 0.05) (Additional file 1: Fig. S2). Compared with different databases, only YOD1 in the OTUD gene family was found to be stably and highly expressed in PAAD.