Reduced sensitivity to CK1 inhibitor IC261 in CK1tau-OX21. A) Dose–response curves of free-running period lengthening of CCA1-LUC (black line), CK1-OX8 (blue line), and CK1tau-OX21 (red line). CK1-OX8 results reproduced from  for direct comparison. B-C) For relevant IC261 concentrations, the averaged raw data (n = 8) is provided for CCA1-LUC parent cells (B) and CK1tau-OX21 cells (C). Black lines indicate the vehicle-treated controls, and blue lines represent inhibited cells. Dashed lines indicate SD (n = 8).