sentences:  methylation of lysine 9 of histone H3) which target the genomic region for heterochromatin formation.The protein complex that binds to siRNAs and interacts with the methylated lysine 9 residue of histones H3 is the RITS complex.RITS was discovered in the fission yeast "Schizosaccharomyces pombe", and has been shown to be involved in the initiation and spreading of heterochromatin in the mating-type region and in centromere formation.