Final answer:
The two main proteins in the SOS response pathway activated by the EGF binding to EGFR are GRB2 and SOS, which cooperate to regulate various cellular processes.
Step-by-step explanation:
The two main proteins involved in the SOS response pathway following the binding of epidermal growth factor (EGF) to the EGF receptor (EGFR) are GRB2 and SOS. The SOS response pathway is a critical signaling mechanism involved in various cellular processes such as cell growth and division, and it is activated in response to growth factors like EGF. GRB2 and SOS function cooperatively to transmit signals from activated EGFR to downstream effectors, which can lead to further cellular responses such as gene expression, cell cycle progression, and cytoskeletal rearrangement. These proteins demonstrate the complexity of cellular signaling pathways and how they can diverge to create different cellular outcomes based on the interplay of multiple pathways and proteins.