The present invention provides for a purified endothelial monocyte activating polypeptide II, wherein the polypeptide has an apparent molecular weight of about 20,000 Daltons. The present invention also provides for an effector cell activating protein comprising a polypeptide having an amino acid sequence wherein at least four amino acid residues are the same as RIGRTVT and are in the same relative positions. The invention also provides for a DNA which encodes the effector cell activating protein. The invention also provides for methods of inducing inflammation in a subject and methods of treating tumors in a subject. The invention also provides for a pharmaceutical composition which comprises the endothelial monocyte activating polypeptide II and a carrier.