Mechanical dissociation was used to isolate biliary epithelium from human CBD, GBD, and PancD (Fig. 1A), which allows the recovery of a near homogenous population of cells coexpressing the cholangiocyte markers, keratin (KRT) 7/KRT19 (94.7% ± 4.31%; mean ± SD; n = 2; Fig. 1B). The gene discussed is KRT19; the disease is red-green color blindness.