The effect of antibody to L-phenylalanine mustard conjugate on malignant cells selectively marked through "early inflammatory-like" vascular permeability.

The concept of destroying a malignant cell in situ while leav ing its normal neighbor intact and functioning has many parallels among well-known immunologie phenomena. It is, therefore, not surprising that for well over 50 years an immunologie approach has held a logical attraction for students of cancer. Immunologie studies have, for a large part, concentrated on the antigenic structure of the cancer cell, considering the question of the pres ence or absence of tumor-specific antigens. There is now ample evidence for antigenic loss (15, 17) as well as antigenic fortifica tion (23) and gain (6), and, further, it is now clear that these features may be seen simultaneously. Although there is no doubt that spécifie antigens exist in certain experimental tumors, as documented by Old and Boyse (16), and probably also in spon taneously occurring human tumors (5, 7), there is no complete explanation for the lack of an effective immunologie response by the host. Whether this is because of a lack of antigen release, immunologie paralysis, tolerance, or still another factor, remains to be seen. In recent years, a persistent effort has been made to discover a method which would produce an effective host reaction against cancer cells. Nevertheless, it is reasonable to say that such attempts to use immunologie processes in the treatment of