This article has been retracted at the request of the Authors.
The above paper describes synthesis of a series of substituted calixarenes, which were fully characterized and their binding to the human receptor CD69 and respective interactions. Unfortunately, we have learned recently that the author responsible for the immunological experiments—Prof. Karel Bezouška—has been fabricating the results and most plausibly also manipulating with experimental material in collaborating laboratories. Based on the findings of the joint ethical committee of the Institute of Microbiology, Acad. Sci. of the Czech Republic, and Charles University in Prague we consider all the data on the binding of ligands to the CD69 receptor erroneous and, therefore, we retract the above publication. We would like to apologize to all affected parties.