Following my return to Geneva in 1980 and searching for a high level of IL-1 in urine and serum of patients with high fever or Still's disease, to our surprise-"a finding of absence"-we found that IL-1 was masked by a factor of approximately 17 kDa and first presented this in 1984 at the Fourth International Lymphokine Workshop. Here, IL1B is linked to systemic-onset juvenile idiopathic arthritis.