Prosomes were found as mRNA-associated ribonucleoprotein particles (RNP) and cofactors of untranslated (ribosome-) free mRNP. Previous data have shown the presence of prosomal networks in the cytoplasm of PtK1 and HeLa cells and their superposition onto the intermediate filaments (IF) of cytokeratin type but little if any of vimentin type. Here it is shown that in LLC-MK2 cells various prosomal antigens are present on both, vimentin and cytokeratin networks, individual prosomal antigens superposing to variable degrees onto the IF subnetworks. Some prosomal antigens in variable relative concentrations were also observed in the nuclei of these cells. We suggest the existence of prosomal subnetworks specific for each prosomal antigen superposing to a variable extent onto the IF of both types.