Apical polarity of the t-SNARE syntaxin 3 may have implications for cancer immunotherapy. In situ immunofluorescence analysis reveals that syntaxin 3 (green) is localized to the apical surface of prostatic epithelial cells lining the luminal interface of the gland while E-cadherin (red) is localized in its typical basolateral pattern (top figure). Polarity of these antigens is similar in cultured MDCK cells expressing exogenous rat syntaxin 3 (bottom figure). Disrupting microtubule integrity with commonly used chemotherapeutic drugs alters the localization of syntaxin 3 and the polarized delivery of at least some apical transmembrane proteins, including an important tumor associated antigen overexpressed in most cases of prostate cancer. For details, see Christiansen et al. in this issue.