P2RX7 and polycystic kidney disease: CRISPR/Cas9 has been used to globally delete the P2rx7 gene in PCK/CrljCrl-Pkhd1pck/Crl (PCK) rats, derived from Sprague–Dawley rats encoding a mutation in the Pck locus and serving as a model of inherited polycystic kidney disease [163].