sentences:  Third generation pegylation agents, where the polymer has been branched, Y shaped or comb shaped are available and show reduced viscosity and lack of organ accumulation.Unpredictability in clearance times for PEGylated compounds may lead to the accumulation of large molecular weight compounds in the liver leading to inclusion bodies with no known toxicologic consequences.Furthermore, alteration in the chain length may lead to unexpected clearance times "in vivo".