Examples include membrane associated receptors, transporter proteins (e.g., ion and other channels such as potassium, sodium, proton, chloride channels, pores; active transporters such as TEXAN drug transporters, mini-TEXANS and ABC drug transporters and antiporters such as the H+/glucose antiporter); enzymes (e.g. leucotriene C4 synthase); and immunogens (e.g. tumor metastasis-associated antigen)