Studies in cancer biology clearly indicate the pathologic powers of abnormal ErbB signaling and its contribution to oncogenesis, asthma, injury repair, and rheumatoid arthritis (Stoll and Elder, 1998; Davies et al., 1999; Satoh et al., 2001; Bersell et al., 2009; Calvo et al., 2010; Finigan et al., 2011; Yarden and Pines, 2012). Here, EGFR is linked to rheumatoid arthritis.