 In addition, Piwi associates with Heterochromatin protein 1, an epigenetic modifier, and piRNA-complementary sequences.These are indications of the role Piwi plays in epigenetic regulation.Piwi proteins are also thought to control the biogenesis of piRNA as many Piwi-like proteins contain slicer activity which would allow Piwi proteins to process precursor piRNA into mature piRNA.