They are thought to affect signaling processes, damaging neurons and resulting in degeneration that causes the spongiform appearance in the affected brain.The CJD prion is dangerous because it promotes refolding of native prion protein into the diseased state. The number of misfolded protein molecules will increase exponentially and the process leads to a large quantity of insoluble protein in affected cells. This mass of misfolded proteins disrupts neuronal cell function and causes cell death. Mutations in the gene for the prion protein can cause a misfolding of the dominantly alpha helical regions into beta pleated sheets. This change in conformation disables the ability of the protein to undergo digestion. Once the prion is transmitted, the defective proteins invade the brain and induce other prion protein molecules to misfold in a self-sustaining feedback loop. These neurodegenerative diseases are commonly called prion diseases.People can also develop CJD because they carry a mutation of the gene that codes for the prion protein (PRNP). This occurs in only 5–10% of all CJD cases. In sporadic cases, the misfolding of the prion protein is a process that is hypothesized to occur as a result of the effects of aging on cellular machinery, explaining why the disease often appears later in life. An EU study determined that "87% of cases were sporadic, 8% genetic, 5% iatrogenic and less than 1% variant."
Tobi may refer to:

Tobi (given name), a unisex name
Tobi (island), island in the Palauan state of Hatohobei
Tobian language, the language of Tobi
Hatohobei, an island and the southernmost of Palaus sixteen states
Tobi (month), in the Coptic calendar
Tobi!, a 2009 television series
Tobramycin, an antibiotic drug that is sold under the brand name "Tobi"
Tobi (Naruto), the alias of Obito Uchiha, one of the primary antagonists in the anime and manga series Naruto Shippuden
ToBI, a standard for transcribing English intonation
Tobi shokunin or tobi for short; construction workers in Japan
Tobi trousers, the typical piece of clothing of tobi shokunin
Texas Oilmans Bass Invitational (TOBI)
Tobi (1978 film)

See also
Tobias
Toby (disambiguation)