Nuclear transcription factor Y subunit beta is one subunit of a trimeric complex, forming a highly conserved transcription factor that binds with high specificity to CCAAT motifs in the promoter regions in a variety of genes.

This gene product, subunit B, forms a tight dimer with the C subunit, a prerequisite for subunit A association. The resulting trimer binds to DNA with high specificity and affinity. Subunits B and C each contain a histone-like motif. Observation of the histone nature of these subunits is supported by two types of evidence; protein sequence alignments and experiments with mutants.Li et al. (1991) assigned the NFYB gene to human chromosome 12 by in situ hybridization.