|EGFR → EGFR → SRC → TIAM1 → RAC1||
EGFR → EGFR
EGFR is a part of EGFR bound to EGFR.
EGFR → SRC
EGFR bound to EGFR phosphorylates SRC on Y419.
SRC phosphorylated on Y419 is active.
SRC → TIAM1
Active SRC phosphorylates TIAM1.
Phosphorylated TIAM1 is active.
TIAM1 → RAC1
Active TIAM1 activates RAC1.