TIMELESS and its partner TIMELESS interacting protein (TIPIN) interact with components of the DNA replication system to regulate DNA replication processes under both normal and stress conditions and are essential for ataxia telangiectasia and Rad3-related (ATR)-checkpoint kinase (Chk)1 and ataxia telangiectasia mutated (ATM)-checkpoint kinase (Chk)2-mediated signaling and S-phase arrest [16-19]. Here, TIPIN is linked to telangiectasis.