To investigate whether increased RhoA protein abundance in ARPKD tissues really induces disruption of F-actin formation, we used siRNA to decrease RhoA levels in a cholangiocyte cell line derived from PCK rats, a Sprague-Dawley strain (Crj:CD/SD) with a spontaneous Pkhd1 mutation33, 34. Here, PKHD1 is linked to autosomal recessive polycystic kidney disease.