DDR1 and cyst: However, despite the upregulation of both DDR1 protein and DDR1 kinase activity in vivo in mouse models of ADPKD, targeted deletion of DDR1 using CRISPR/Cas9 did not slow cyst growth or preserve kidney function in both an “early rapid” and “late slow” mouse model of ADPK in which PKD1 was conditionally deleted embryonically by Pkhd1-Cre or after post-natal day 28 by feeding doxycycline to Pax8rtTA; TetO-cre; PKD1fl/fl mice respectively.