In a placebo-controlled, dose-escalation phase 1 clinical trial in adult patients with long-standing T1D, we demonstrated the safety and feasibility of two vaccinations (prime and boost) with tolDCs pulsed with a proinsulin peptide and identified immune correlates of the mechanistic immunological efficacy of intradermally injected tolDCs [10,11]. The gene discussed is INS; the disease is type 1 diabetes mellitus.