Consistent with previous reports (Kikis et al., 2005; Thines and Harmon, 2010; Dixon et al., 2011; Kolmos et al., 2011; Herrero et al., 2012), both null mutants, elf3-1 and elf3-4, displayed arrhythmia with reduced levels of CCA1::LUC and LHY::LUC and high levels of TOC1::LUC, GI::LUC, PRR7::LUC, and PRR9::LUC, compared to Bay-0 (Figure 10). The gene discussed is PRR9; the disease is cardiac arrhythmia.