Thank you for adding your knowledge Paul.
I know nothing about the action of pain killers, or pain pathways.
Re your post
http://lib.bioinfo.pl/auth:Farooqui,M "Naxalone acts as an agonist of oestrogen receptor acivity in MCF7 cells" Naxalone is stated to be an opioid receptor antagonist.
There is a parallel possible activity involving the sex hormone pathways. Intervention in the COX pathways has been shown to affect hormone levels. Opiod analgesics have been suggested to be able to impact in the hormone pathways, and it has been suggested as being a possible concern in Sports testing for example.
From the above it appears that morphine may intervene in the hormone pathways.
I looked morphine up on Wikipedia and it appears it intervenes in the immune pathways that have commonunlatites with COX pathways and products.
RB