Cancers are extremely heterogeneous in terms of the frequency and types of mutations present in different malignant tumors. Thus, it is likely that uniform clinical treatment is not optimal for all patients, and that the development of individualized therapeutic regimens may be beneficial. Multiple, unique small peptides bind to cell lines derived from different colon adenocarcinomas. Within two hours of contact, the colorectal cancer cells are able to transfer a 32P radioisotope from the small peptides to cellular proteins; the transfer occurs at a substantially higher rate than in the colorectal cancer cells than in cell lines derived from other cancers or from normal tissues.