Surprisingly, the present inventors have discovered that expression of TAT-001 protein in human patients is associated with cancer, and that the overexpressed protein is present in plasma membrane fractions. Thus, the present inventors have discovered that TAT-001 is associated with abnormal development and growth, and may be useful as a target for the identification of anti-cancer compounds, including antibodies for use in immunotherapy. Accordingly, the present invention provides methods for the identification of compounds that inhibit TAT-001 expression or activity, comprising: contacting a candidate compound with a TAT-001 and detecting the presence or absence of binding between said compound and said TAT-001, or detecting a change in TAT-001 expression or activity. Methods are also included for the identification of anti-cancer compounds and compounds that modulate TAT-001 expression or activity, comprising: administering a compound to a cell or cell population, and detecting a change in TAT-001 expression or activity.