MAPK1 and pachyonychia congenita: Additionally, CRT was co-stained with pEGFR1173 (with EGF), Fibronectin and Integrinβ1 by IF under confocal microscopy and was co-immunoprecipitated with Fibronectin, Integrinβ1 and c-Myc in both PC cells, all of which indicating a close interaction of CRT with Integrin/EGFR–ERK/MAPK signaling pathway in PC.