摘要MicroRNAs (miRNAs) are a class of endogenous non-coding RNAs with regulatory functions. Traditionally, miRNAs are thought to play a negative regulatory role in the cytoplasm by binding to the 30UTR of target genes to degrade mRNA or inhibit translation. However, it remains a challenge to interpret the potential function of many miRNAs located in the nucleus. Recently, we reported a new type of miRNAs present in the nucleus, which can activate gene expres-sion by binding to the enhancer, and named them nuclear activating miRNAs (NamiRNAs). The discovery of NamiRNAs showcases a complementary regulatory mechanism of miRNA, demon-strating their differential roles in the nucleus and cytoplasm. Here, we reviewed miRNAs in nucleus to better understand the function of NamiRNAs in their interactions with the enhancers. Accord-ingly, we propose a NamiRNA–enhancer–target gene activation network model to better under-stand the crosstalk between NamiRNAs and enhancers in regulating gene transcription. Moreover, we hypothesize that NamiRNAs may be involved in cell identity or cell fate determina-tion during development, although further study is needed to elucidate the underlying mechanisms in detail.