It’s that Y chromosome.
If you are male it is there.
Some say you can be LOY (Low Y Chromosome)
But you are right, You cannot make a female out of a male or a male out of a female.
Have read that those who try to, are a lot more apt to commit suicide.
They are crazy, mentally unstable.
Are you sure that isn’t SOY instead of LOY?
Never let boys eat soy if you can help it. At least if you’re European or African. I occasionally wonder if there is a gene for soy tolerance in parts of Asia that block the detrimental effects on young males.
Somewhere out there, is a surgeon without a compass.