EGFR and pemphigus: However, multiple lines of evidence point towards a pemphigus autoantibody‐induced aberrant signalling in keratinocytes after antibody binding to the target antigen(s) (Pollmann et al., 2018), and this signalling involves p38 MAPK, PKC, cJNK, RhoA, and several caspases, as well as signalling downstream of the epidermal growth factor receptor (Berkowitz et al., 2005; Cirillo, Lanza, & Prime, 2010; Grando, 2012; Hariton et al., 2017; Sayar et al., 2014).