Nucleolar Protein 3 is encoded by NOL3 gene; multiple transcript variants encoding different isoforms have been found for this gene. So far, Nucleolar protein 3 has show to have two Isoforms. Isoform 1 may be involved in RNA splicing.Isoform 2 may inhibit apoptosis.It has been shown to down-regulate the enzyme activities of caspase 2, caspase 8 and tumor protein p53.