Plasma Cell Tumor Development: A Complex Multi-Step Process

What Causes Cancer?

Potter now knew a great deal about immunoglobulins. He knew that they are antibodies that bind to antigens. He knew each one attaches to only one kind of antigen. He knew their three-dimensional structure and basic genetic composition. But there was one question that he still could not answer: Why were the BALB/cAn mice the only ones that developed plasma cell tumors when injected with mineral oil or plastic shavings? In other words, what caused the tumors to develop? The answer would open new fields in cancer and immunology.

“He tirelessly examined tens of thousands of stained tumor slides. Towers of stacked slideboxes teetered around him and occasionally came crashing down.”

• —Gary Jones, NCI

Olympus Compound Microscope

Potter was usually at his laboratory bench using this microscope. Shown are plasma cells with darkly stained nuclei. The clear spots next to the nucleus are perinuclear “hoffs” and are filled with newly synthesized protein, in this case, antibody.