A gene (designated 161P2F10B) and its encoded protein are described wherein 161P2F10B exhibits tissue specific expression in normal adult tissue, it is aberrantly expressed in the cancers listed in Table I. Consequently, 161P2F10B provides a diagnostic, prognostic, prophylactic and/or therapeutic target for cancer. The 161P2F10B gene or fragment thereof, or its encoded protein or a fragment thereof, can be used to elicit a humoral or cellular immune response.