Abstract: Heterogeneous nuclear ribonucleoprotein (hnRNP) is a family of multifunctional nuclear RNA-binding proteins that regulate the alternative splicing of pre-mRNA and the transport, translation, and stability of mRNA. The most abundant and best characterized proteins of this group are hnRNP A1 and hnRNP A2, which share a high degree of sequence homology and functional similarity. HnRNP A1 and hnRNP A2 are upregulated in multiple human tumors and modulate the alternative splicing and mRNA stability of various tumor-related genes critical to tumor cell growth, apoptosis, inflammatory and immune reactions, and epithelial-to-mesenchymal transition. Therefore, hnRNP A1 and hnRNP A2 have potential diagnostic, prognostic, and therapeutic values.