protein cytotoxic granule associated RNA binding protein TIA1 TIA1 RNA-binding protein TIA-1 protein nucleolysin TIA-1 isoform p40 Category=gene. TIA-1 PR:000029793 p40-TIA-1 T-cell-restricted intracellular antigen-1 A protein that is a translation product of the human TIA1 gene or a 1:1 ortholog thereof.