TABLE 2.

Characteristics of an “ideal” cancer antigen

CRITERIA	TOP SUB-CRITERIA
THERAPEUTIC FUNCTION	Superb Data Controlled vaccine trial suggestive
IMMUNOGENICITY	T cell and/or Ab responses elicited in clinical trials
ONCOGENICITY	Associated with oncogenic process, i.e., oncogenic “self” protein
SPECIFICITY	Absolutely specific, e.g., mutated oncogene, idiotype protein or viral protein
EXPRESSION LEVEL & % POSITIVE CELLS	Highly expressed on all cancer cells in patients designated for treatment
STEM CELL EXPRESSION	Evidence for expression on putative cancer stem cells
NUMBER OF PATIENTS WITH ANTIGEN POSITIVE CANCERS	High level of expression in many patients with a particular tumor type
NUMBER OF EPITOPES	Longer antigen with multiple epitopes and the potential to bind to most MHC molecules
CELLULAR LOCATION OF EXPRESSION	Normally expressed on the cell surface with no or little circulating antigen