In the present invention, wasted power consumption caused when a clock and data recovery unit in an optical network unit in a PON system is activated from a power-saving state is reduced and rapid, secure communication is performed. Provided is an imaging device comprising: a first Compton camera for receiving one gamma ray emitted from an imaging target administered by first probe having positron emitting nuclei and second probe having gamma ray emission nuclei; and a second Compton camera which is arranged opposite to the first Compton camera and receives another gamma ray emitted from the imaging target. The peripheral cable connects to the computer interface for communications with the host computer. Also provided are breast cancer and other cancer markers and antibodies that specifically recognize these markers.