Ethanol drinking in WT and Sig-1R KO mice (n=9–10/genotype). (A, B) Mice were given access to escalating concentrations of ethanol (3%, 6% and 20% v/v) in a home cage, two bottle choice paradigm. (C, D) Mice were given access for 14 consecutive days to a 10% v/v ethanol solution in a two bottle choice paradigm. Data represent Mean ± SEM. $ p≤0.1, * p≤0.05, ** p≤0.01, *** p≤0.001 vs. WT mice (Student’s t test).