|EGFR → EGFR → KRAS → KRAS → RAF1
EGFR → EGFR
EGFR is a part of EGFR bound to SOS1.
SOS1 bound to EGFR is active.
SOS1 → KRAS
Active SOS1 activates KRAS in the membrane.
KRAS → KRAS
KRAS is a part of KRAS bound to RAF1.
KRAS → RAF1
KRAS bound to RAF1 has a component RAF1.