A novel gene (designated 85P1B3) and its encoded protein are described. While 85P1B3 exhibits tissue specific expression in normal adult tissue, it is aberrantly expressed in multiple cancers including set forth in Table 1. Consequently, 85P1B3 provides a diagnostic and/or therapeutic target for cancers. The 85P1B3 gene or fragment thereof, or its encoded protein or a fragment thereof, can be used to elicit an immune response.