This present invention relates to compounds (e.g., TM4SF1 binding proteins, e.g., anti-TM4SF1 antibodies) that specifically bind to a polypeptide at an epitope including an amino acid sequence of SEQ ID NO : 1. In particular, the compounds of the invention are capable of being internalized into a TM4SF1-expressing cell (e.g., a tumor cell or an angiogenic vasculature endothelial cell) following binding to the epitope of including the amino acid sequence of SEQ ID NO : 1. The invention also provides methods of treating a subject having a disorder associated with pathological angiogenesis with the compounds of the invention.