TUT7 is a terminal uridylyltransferase that catalyzes 3' uridylation of RNAs to regulate their stability and function. Its primary role is marking deadenylated mRNAs with short poly(A) tails (<25 nucleotides) for degradation through oligo-uridylation, facilitating global mRNA decay 1. TUT7 employs three distinct uridylation mechanisms to regulate precursor miRNA (pre-miRNA) biogenesis: mono-uridylation of group II pre-miRNAs to restore canonical structures promoting Dicer processing, oligo-uridylation of excessively trimmed pre-miRNAs to trigger degradation, and LIN28A-enhanced oligo-uridylation of pre-let-7 to suppress let-7 biogenesis 2. TUT7 also participates in miRNA-induced silencing through uridylation of deadenylated miRNA targets 1. Additionally, TUT7 cooperates with the 3'-5' exonuclease 3'hExo in histone mRNA maintenance and degradation 3, and with PATL2 and CPEB1 in maintaining mRNA homeostasis during oocyte maturation 4. Recent studies identify TUT7 as a vulnerability target in FOCAD-deficient cancers, where it functions as a salvage mechanism degrading aberrant RNA 5. Due to functional redundancy with TUT4, distinguishing individual TUT7 roles remains challenging 6.