PKHD1 and autosomal recessive polycystic kidney disease: Consistently, we identified truncating genetic variants specifically affecting the cytoplasmic tail in ARPKD patients, found SRC and the cytoplasmic tail of fibrocystin in a joint dynamic protein complex and observed increased activation of both SRC and STAT3 in cyst‐lining renal epithelial cells of ARPKD patients.