The work presented here is based upon contact with excellent scientists who did not measure their time sparingly to be of assistance. It has also benefited from the infrastructure some col- leagues made available to me, and without which considerable delays and expenditure would have been unavoidable. In this respect, I am particularly indebted to a number of people. Dr. J. Abramovici, Professor S. Orloff and Professor R. Fridrich reviewed my data critically and gave me access to their Insti- tutes, enabling me to collect the clinical evi- dence required to complete this work. The latter benefited also from the efforts of Dr. K. Streule who supervised the cross-over study upon which the final conclusions have been based. Dr. R. Senekowitsch and her staff were of inva- luable help with the animal experimental data and was, together with Professor H. Kriegel, kind enough to enable me to complete this particular part. Dr. H.L. Chia's laboratory data provided me with the possibility to widen the radiopharmaceu- tical aspects of the theme under discussion. I am also indebted to Dr. K.J. Panek for personal com- ments regarding the radiation dosimetry of lll- v vi SCINTIGRAPHY OF INFLAMMATION labelled leukocytes.