The following primary antibodies were used in this study: anti-CENPA (AB13939; Abcam), anti-SC35 (S4045; MilliporeSigma), anti-MFAP1 (HPA042370; MilliporeSigma), anti-SRRM2 (PA5-68009; Thermo Fisher Scientific), anti-ZNF207 (HPA017013; MilliporeSigma), anti-HP1α (H2164; MilliporeSigma), anti-β Tubulin (AB18207; Abcam), anti-FITC (200-002-037; Jackson ImmunoResearch), custom-made anti-SON (Chen et al., 2018 (link); PACIFIC10700; Pacific Immunology), anti-Nucleophosmin (AB86712; Abcam), anti-nucleolin (AB70493; Abcam), anti-Coilin (Ab87913; Abcam), and anti-PRPF38A (PA5-62730; Thermo Fisher Scientific). Secondary antibodies used were goat anti-mouse HRP (115-035-062; Jackson ImmunoResearch), goat anti-rabbit HRP (111-035-144; Jackson ImmunoResearch), goat anti-mouse FITC (111-095-144; Jackson ImmunoResearch), and goat anti-rabbit Texas red (115–075-146; Jackson ImmunoResearch).