I am doing western blot to test mTORC1 function on HEK 293T cells, but p-S6K and p-4EBP1 signal that I got are often not persistent. Such as, p-S6k did not change when p-4EBP1 decreases. Could we just pick p-4EBP1 or p-S6K for showing mTORC1 function status ?