hnRNP C1/C2 is a member of the subfamily of ubiquitously expressed heterogeneous nuclear ribonucleoproteins (hnRNPs). hnRNP C1/C2 is essential components of the heterogeneous nuclear ribonucleoprotein complexes, playing a critical role in the processing and transport of pre-mRNA. These proteins are primarily located in the nucleus, where they bind to heterogeneous nuclear RNA (hnRNA) produced by RNA polymerase II, facilitating the assembly of spliceosomal complexes necessary for mRNA maturation. The ability of hnRNP C1/ C2 to shuttle between the nucleus and cytoplasm is vital for regulating gene expression, as this movement allows for dynamic response to cellular signals and modulation of mRNA stability and translation.