PTGDR and pachyonychia congenita: Thereby, to further confirm the regulatory model of which SOX21-AS1 on SOX21 in PC cells, we confirmed the cellular location of SOX21-AS1 in PC cells via FISH assay along with subcellular fractionation analysis, which confirmed the main location of SOX21-AS1 in the cytoplasm, suggesting the possibility of SOX21-AS1 regulating SOX21 at a post-transcriptional level (Fig. 2G, H).