<prompt> Answer this question truthfullyWhat classification does monoclonal gammopathy of undetermined significance fall into?  <response>: <reason> Monoclonal gammopathy of undetermined significance MGUS may be classified according to cytogenetic differences into the following subtypesgroups: If the staging system involves specific and characteristic findings and features:There is no established system for the staging of monoclonal gammopathy of undetermined significance MGUS. 