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
Byne's disease high humidity can also affect pyrite (or its more reactive polymorph marcasite) (iron sulphide) fossils in a somewhat similar condition, which is known as pyrite disease. The iron sulfide can react with water and oxygen to form iron sulfates and sulfuric acid, which then can produce Bynesian decay. Byne's disease Byne's disease, more accurately known as Bynesian decay, is a peculiar and permanently damaging condition (resulting from an ongoing chemical reaction) which often attacks mollusk shells that are in storage or on display for long periods of time. Bynesian decay is a form of efflorescence of salts formed by the