A protein found on some T cells and B cells (two types of white blood cells). It is a receptor for a protein called tumor necrosis factor, which is involved in cell growth and cell survival. The CD30 protein may be found in higher than normal amounts on some types of cancer cells, including lymphoma cells. Knowing how much CD30 protein is on a patient’s cancer cells may help diagnose cancer and plan treatment. The CD30 protein is a type of tumor necrosis factor receptor and a type of tumor marker.