Are FICA taxes deductible or only Federal and State Income Tax?

[Kunal Patel]

Hello, 

Does anyone know what taxes are deductible through business expense? For example, if you have a W2 job and make 100K. Then you pay 24% on the 15K from the 85K to 100K bracket of your income. Adding the FICA tax would be 31%. If you have 15K of business expense after income, would you be deducting the 31% or the 24%?

Thanks!

Kunal