A novel gene (designated 125P5C8) and its encoded protein, and variants thereof, are described wherein 125P5C8 exhibits tissue specific expression in normal adult tissue, and is aberrantly expressed in the cancers listed in Table I. Consequently, 125P5C8 provides a diagnostic, prognostic, prophylactic and/or therapeutic target for cancer. The 125P5C8 gene or fragment thereof, or its encoded protein, or variants thereof, or a fragment thereof, can be used to elicit a humoral or cellular immune response anti-bodies or T cells reactive with 125P5C8 can be used in active or passive immunization.
