UNC93B1 and nephritis: It is also noteworthy that proband A.III.1 in our study with a heterozygous UNC93B1+/T93I mutation developed early-onset isolated cutaneous tumid lupus (as did her two siblings with ANA seropositivity, and her father), whereas both UNC93B1E92G/E92G siblings described by Wolf et al. (2024) developed systemic lupus with nephritis and several other organ-threatening manifestations.