RARRES2 mRNA and protein are broadly expressed in PT cells. (A) RNA transcript distribution of RARRES2 in normal primate PT cells across scRNA-seq data sets. (B) Confocal micrograph immunolabeled with anti-PTH-, anti-RARRES2-, and DAPI-stained nuclei on slide from formalin-fixed paraffin-embedded normal primate PT tissue and pixel-wise colocalization heatmap of PTH and RARRES2 from a 21-slice Z-stack with 90 nm pixel size and 0.30 µm slice spacing. Scale bar, 30 µm. The vertical and horizontal lines indicate thresholds determined for each channel by Costes regression analysis, below which to not consider colocalization, and the diagonal line with slope 1.034 and Pearson's R = 0.617 indicates the best fit for pixels above thresholds in each channel.