In addition, S-phase kinase-associated protein 2 (Skp2) specifically degrades cyclin-dependent kinase inhibitor 1B (CDKN1B) (Singh et al., 2018), and mindbomb homolog 1 (MIB1) enhances the ubiquitin-mediated degradation of suppression of tumorigenicity 7 (ST7) (Zhang et al., 2021b); both Skp2 and MIB1 promote tumor proliferation. This evidence concerns the gene CDKN1B and neoplasm.