The dataset uploaded here is mass spectrometry data from Coilin BioID experiments comparing siControl (siCT) and si7SK snRNA knockdown conditions. The purpose of this analysis is to investigate how depletion of 7SK snRNA affects the composition of Cajal body-associated factors. By comparing the two conditions, we aim to identify proteins whose association with Coilin—and potentially with Cajal bodies—is altered when 7SK is knocked down.