Replication initiator 1 is a protein that in humans is encoded by the REPIN1 gene. The protein helps enable RNA binding activity as a replication initiation-region protein. The make up of REPIN 1 include three zinc finger hand clusters that organize polydactyl zinc finger proteins containing 15 zinc finger DNA- binding motifs.  It has also been predicted to help in regulation of transcription via RNA polymerase II with it being located in the nucleoplasm. Expression of this protein has been seen in the colon, spleen, kidney, and 23 other tissues within the human body throughout.