  We summarize and expand known connections between the study of Dehn surgery
on links and the study of trisections of closed, smooth 4-manifolds. In
addition, we describe how the potential counterexamples to the Generalized
Property R Conjecture given by Gompf, Scharlemann, and Thompson yield genus
four trisections of the standard four-sphere that are unlikely to be standard.
Finally, we give an analog of the Casson- Gordon Rectangle Condition for
trisections that can be used to obstruct reducibility of a given trisection.
