CD99 and Familial short QT syndrome: Although the roles of most PAR1 genes have not yet been elucidated, the dysregulation of SLC25A6 and CD99 has been linked to frequent KS traits, such as cardiac abnormalities, short QT syndrome (Zitzmann et al., 2015; Skakkebæk et al., 2018), and autoimmune diseases (Lefèvre et al., 2012; Lefèvre et al., 2019).