Other infectious causes: Lung abscess (an infection in which cells of a part of the lung die) Round pneumonia (infection caused by virus or bacteria; air spaces of the lungs are filled with fluid and cells) Hydatid cyst (a cyst formed by the larval stage of a tapeworm, Echinococcus) Inflammatory (noninfectious):
Walter White is a talented chemist who, as a graduate student at the California Institute of Technology, contributed with the research that helped a team win a Nobel Prize in Chemistry. After graduating school, Walter founded the firm Gray Matter Technologies with Elliott Schwartz, his former classmate and close friend.
Gretchen Schwartz is Walter White's old college chemistry assistant and now co-owner of Gray Matter Technologies, a successful pharmaceutical company. A former romantic interest of Walt's, she is currently married to Elliott Schwartz, with whom she also manages Gray Matter. Gretchen was introduced via a flashback.