Provided herein are compositions and methods for creating immunogens representing regions of a target protein not targeted by available antibodies, and use of the same to generate antibodies specific for regions.本發明提供用於產生免疫原之組合物及方法,該等免疫原代表不被可利用之抗體靶向之目標蛋白質區域,及使用該等組合物及方法產生對該等區域具有特異性的抗體。