A novel human serrate-2 polypeptide consisting of a polypeptide containing the amino acid sequence described in SEQ ID NO:1 in the Sequence Listing and having the effect of regulating the differentiation of undifferentiated cells involving stem cells; its gene; a process for producing the same; and an antibody specifically recognizing the polypeptide. The cabinet houses equipment, and the fan cools the equipment. Thus, a space in the drying chamber 42 can be insulated from a space of the cleaning bath 41 through rotary doors 59a and a slide door 72. A reference value for a reference parameter associated with presentation of the media files together is used to synchronize the media files \u201con the fly\u201d as the media files are received at the user’s computing device. The connection points provide electrical communication between a lead connector end of an implantable medical lead and one or more leads of a testing device in such a manner as to minimize potential damage to the lead connector end.