EWSR1's visual modalities are defined by its association with nucleic acids and RNA polymerase II.

Rajan et al. report the visualization of endogenous EWSR1. EWSR1 exists in two visual modalities in the nucleoplasm, one distributed and one as foci. Both EWSR1 modalities localize with nascent RNA. EWSR1 foci concentrate in regions of euchromatin and colocalize with phosphorylated RNA polymerase II.