Gender Bias comes though into play in data because data is not collected about women at the same rate it collected about men. Men are the default for testing crash dummies and for most drug testing. This means that the systems are built to them, not for women. 

Articles

We Need to Close the Gender Data Gap By Including Women in Our Algorithms

The Pitfalls of Data's Gender Gap

Gender Shades (MIT Thesis, Joy Buolamwini)

Why Algorithms Can Be Racist and Sexist

Sex and gender differences and biases in artificial intelligence for biomedicine and healthcare