Man bitten by dog? One may indicate disease (9)
I believe the answer is:
biomarker
'one may indicate disease' is the definition.
I know nothing about this answer so I cannot tell whether this works.
'man bitten by dog?' is the wordplay.
'man' becomes 'iom' (abbreviation for Isle of Man).
'bitten by' is an insertion indicator (I've seen this in other clues).
'dog?' becomes 'barker' (I've seen this before).
'iom' put inside 'barker' is 'BIOMARKER'.
Can you help me to learn more?
(Another definition for biomarker that I've seen is " One may show sign of disease".)