Your complement system consists of a group of important proteins in your bloodstream. These proteins help your immune system fight off harmful invaders, such as bacteria, and other foreign substances.

Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Thomas J Catalano is a CFP and Registered ...

Venn diagrams are used to sort sets of data. The probability of an event not happening uses the complement of the region on the Venn diagram. Count the number of elements in each region. Redraw the ...