KP4, Kp4 or kp4 may refer to * Killer toxin Kp4 family, a family of killer toxins, which includes the Kp4 killer toxin from the smut fungus ''Ustilago maydis'' * KP4, an amateur radio call sign assigned to operators in Puerto Rico, see Amateur radio licensing in the United States#Call signs * ''

Witness In law, a witness is someone who, either voluntarily or under compulsion, provides testimonial evidence, either oral or written, of what they know or claim to know. A witness might be compelled to provide testimony in court, before a grand jur ...

'' (#KP4), Katy Perry's fifth studio album

See also