In addition, we isolated duct‐like cell‐fibroblast clusters from 4‐week‐old KC mice using mechanical dissociation and Fluorescence‐Activated Cell Sorting (FACS) with anti‐EpCAM/PDGFRα antibodies (Figure S15, Supporting Information) for cyst formation analysis and 3D spheroid assay. Here, EPCAM is linked to cyst.