For example, in cancer patients, competitive immunoassays are often detectable for TNF‐α, but ELISA assays detect no TNF‐α in plasma of cancer patients, in agreement with the bioassay data.[88] Engelberts et al.[110] studied these effects and showed that TNF‐α bound to the p55 TNF receptor was not well recognized by sandwich ELISA assays. The gene discussed is TNF; the disease is cancer.