Co-immunoprecipitation experiments performed to determine the ability of SIM2s-HF and variants to dimerize with ARNT2. FLAG immunoprecipitation followed by western blots for ARNT2, HA (SIM2s-HF) and Tubulin were performed. Blots are representative of 3 independent experiments. (A) Expression of SIM2s-HF and the E19K, E224K, W306R and V326M variants induced by dox. (B) SIM2s-HF and R163X variants expressed at a 1 : 5 ratio.