PNRC1 (proline rich nuclear receptor coactivator 1) is a nuclear receptor coactivator and tumor suppressor that regulates ribosome biogenesis and cell proliferation. Mechanistically, PNRC1 recruits the cytoplasmic DCP1α/DCP2 mRNA decapping complex to the nucleolus, where it promotes decapping of specific snoRNAs (U3 and U8) to suppress ribosomal RNA maturation and limit ribosome biogenesis 1. This nucleolar translocation of decapping machinery acts as a gatekeeper that restrains oncogenic proliferation triggered by RAS and MYC 12. PNRC1 exhibits pervasive hemizygous deletions and reduced expression in multiple cancer types 1, and functions as a direct target of the p53-RFX7 tumor suppressor signaling axis 3. Disease relevance extends beyond cancer: PNRC1 was identified as a key gene involved in both osteoarthritis and COVID-19 pathogenesis, with high expression in neutrophils suggesting immune dysfunction involvement 4. Additionally, PNRC1 expression is suppressed by YAP/TAZ oncogenes in colorectal cancer to promote processing body formation and tumorigenesis; PNRC1 reexpression disrupts this pathway and attenuates tumor growth 5. Clinically, PNRC1 reactivation or processing body disruption represents a potential therapeutic strategy for YAP-driven tumors 5.