Mouse tissue extract (50 μg) was separated by 7.5% SDS-PAGE, and the membranes were blotted with DLL1 antibody (GTX133745) diluted at 1:500 and competitor's antibody (sc-9102) diluted at 1:100. The HRP-conjugated anti-rabbit IgG antibody (GTX213110-01) was used to detect the primary antibody.