GRB2 and endometriosis: The pathway analysis for all cases of endometriosis revealed two pathways that were also linked to MAPK signaling: Grb2-Sos provides linkage to MAPK signaling for Integrins and p130Cas linkage to MAPK signaling for integrins. These pathways largely overlap (12 out of the 15 genes in each are the same), and reflect different routes through which integrins (adhesion molecules) can activate ERK1 ERK2 MAPK signaling.