DIRP (Domain in Rb-related Pathway) is postulated to be involved in the Rb-related pathway, which is encoded by multiple eukaryotic genomes and is present in proteins including lin-9 of Caenorhabditis elegans, aly of fruit fly and mustard weed. Studies of lin-9 and aly of fruit fly proteins containing DIRP suggest that this domain might be involved in development. Aly, lin-9, act in parallel to, or downstream of, activation of MAPK by the RTK-Ras signalling pathway.

1: Transcription of meiotic cell cycle and terminal differentiation genes depends on a conserved chromatin associated protein, whose nuclear localisation is regulated. White-Cooper H, Leroy D, MacQueen A, Fuller MT; Development 2000;127:5463-5473. PMID:11076766