FLAG/Spy-tagged PQBP1 overexpression HEY cells were adopted for RIP-seq by EZ-Nuclear RIP (Cross-Linked) Kit (Merck Millipore). Briefly, cells were harvested and cross-linked by 0.3% formaldehyde. Nuclei were extracted and lysed by nuclei lysis buffer, and DNA was subjected to sonication to shear to 500-1000 bp fragments. Magnetic beads with anti-FLAG antibody (Cell Signaling Technology) were used to incubate with nuclei lysates. Then DNaseI was adopted to extract RNA. The library was constructed and pair-end sequenced by Novogene Corporation (Beijing, China) on Illumina NovaSeq 6000 platform (Illumina, CA, USA). Agilent Bioanalyzer 2100 system was employed to assess library quality.