SRC and pachyonychia congenita: Recent studies support the role of Gαi proteins in Src induced formation of invadosomes, which are cellular protrusions exhibited in migrating/invading cells, where a transient activation of Cdc42 is implicated downstream of GPCR activation [40]; thus, we cannot rule out the role of Cdc42 downstream of CXCR4 activated Src activation in PC cells.