Behavioral conditioning of immunosuppression is possible in humans.

“These data demonstrate for the first time that immunosuppression can be behaviorally conditioned in humans.”

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Goebel MU, Trebst AE, Steiner J, Xie YF, Exton MS, Frede S, Canbay AE, Michel MC, Heemann U, Schedlowski M. Behavioral conditioning of immunosuppression is possible in humans. FASEB J. 2002 Dec;16(14):1869-73. doi: 10.1096/fj.02-0389com. PMID: 12468450.
10.1096/fj.02-0389com