XRN2 and uveal melanoma: Immunoprecipitation of both p32 and XRN2 in 92.1 and OMM1 cells revealed a 2- and 6-fold enrichment in OMM1 and a 4- and 64-fold enrichment in 92.1 of SAMMSON RNA, respectively, indicating that SAMMSON binding to these factors is conserved in uveal melanoma cells (Fig. 3A and Supplemental Fig. 5A).