The investigation was conducted in a post-facto manner.

He was the leader of the team, ipso facto, he made all the decisions.

He is the de facto leader of the group.

The law cannot be applied ex post facto.

Lack of exercise is a major factor in weight gain.

The factorial of a number is the product of all positive integers less than or equal to that number.

The cost of transportation is an important factor in calculating the overall expenses.

The Rh factor is a protein found on the surface of red blood cells.

The Rhesus factor is an antigen found on the surface of red blood cells.

The knockout factor determines the effectiveness of the treatment.