Last month, Penn Medicine put out a press release heralding a "cancer treatment breakthrough 20 years in the making." In a small clinical trial, three patients with advanced chronic lymphocytic leukemia (CLL) were treated with genetically engineered versions of their own T cells. Just a few weeks after treatment the tumors had disappeared, and the patients remained in remission for a year before the study was published.
The release didn't, however, explain those "20 years in the making." In 1989, Prof. Zelig Eshhar of the Weizmann Institute's Immunology Department first published a paper…