What distinguishes the recruitment of JAK2 from other receptor tyrosine kinases?

• A. JAK2 is covalently bound to the receptor.
• B. JAK2 is recruited non-covalently, unlike other receptor tyrosine kinases.
• C. JAK2 directly phosphorylates the ligand.
• D. JAK2 is part of the receptor's cytosolic domain.

Answer: (B)