AREG and keratosis pilaris: We observed that upregulation of p‐Fak1 [Appendix Fig S3C; with concomitant upregulation of its target genes Psat1, Areg, and Peg10 (Appendix Fig S3D–F; Golubovskaya et al, 2009)] only occurs in PIP2‐stimulated parental KP cells and is further upregulated in PIP2‐stimulated KPΔNF1 clones.