Secretion both DNA and proteins. It was discovered in "Agrobacterium tumefaciens", which uses this system to introduce the T-DNA portion of the Ti plasmid into the plant host, which in turn causes the affected area to develop into a crown gall (tumor). "Helicobacter pylori" uses a type IV secretion system to deliver CagA into gastric epithelial cells, which is associated with gastric carcinogenesis. "Bordetella pertussis", the causative agent of whooping cough, secretes the pertussis toxin partly through the type IV system. "Legionella pneumophila", the causing agent of legionellosis (Legionnaires' disease) utilizes a type IVB secretion system, known as the icm/dot (intracellular
Dieterich's disease Dieterich's disease Dieterich’s disease, also known as avascular necrosis of the metacarpal hand, is an extremely rare condition characterized by temporary or permanent loss of blood supply to the metacarpal head of the metacarpal bone, resulting in loss of bone tissue. The five metacarpal bones are long bones located between the carpals of the wrist and phalanges of the fingers. Collectively, the metacarpals are referred to as the "metacarpus." The metacarpals are important in maintaining grip strength and mobility of the fingers. Dieterich's disease is often confused with Mauclaire disease, which is characterized by symmetrical flattening of all metacarpal heads.