Fig. 1C). Among AR-positive cells, PCAT18 levels incrementally increased from non-neoplastic (BPH1), to androgen-sensitive (22Rv1, LNCaP) and androgen-insensitive (C4-2) PCa cells. We therefore selected LNCaP and its castrate-resistant sub-line C4-2 [26] for lncRNA characterization and functional studies. RNA fractionation and quantification experiments revealed that PCAT18 is mainly located in the cytoplasm of PCa cells (Suppl. Fig. 1 D). Indeed, the PCAT18 expression profile is more similar to the protein-coding RNA GAPDH than to the nuclear-retained lncRNA MALAT1 [27]. Here, GAPDH is linked to posterior cortical atrophy.