None. To answer your question in short.
To become a pilot, all that you need is the financial backing to get your licence.
Anyone who can afford it, can become a pilot in this day and age ( all you need is to be able read & write, know how to do basic sums and some common sense will get you a long way).
You dont need high school or a university degree to get a job with most of the airlines and AOC holders in the world today.
If you do have a degree, I guess you can bull sh!t a bit more during your interview and that might help....
Money = Flying
Flying = Money
Lift Generation = Bank account balance
Pilot Training = Bank account balance