Mostly derisory, cutting latest in investment for diabetes treatment (7)
I believe the answer is:
insulin
'diabetes treatment' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'mostly derisory cutting latest in investment' is the wordplay.
I cannot quite understand how this works, but
'in' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
'for' is the link.
Can you help me to learn more?
(Other definitions for insulin that I've seen before include "Hormone controlling sugar supply" , "Hormone substance injected by diabetics" , "Hormone secreted by the pancreas" , "Hormone that regulates glucose levels" , "Hormone involved in diabetes" .)