Component of the sequence-specific heterotrimeric transcription factor (NF-Y) which specifically recognizes a 5'-CCAAT-3' box motif found in the promoters of its target genes. NF-Y can function as both an activator and a repressor, depending on its interacting cofactors. This is the function of NFYC (nuclear transcription factor Y subunit gamma, Ensembl gene identifier ENSG00000066136).