Intracellular IL-1β levels in PBMCs from CAPS patients. PBMCs from healthy controls (n = 10), mutation-positive patients (n = 6), or a mosaic patient (patient 7) were isolated and cultured in vitro for 24 hours. Flow cytometric analysis of CD14 expression and intracellular IL-1β levels was performed. The ratio of CD14⁺IL-1β^high monocytes (cells in the right upper quadrant) in healthy controls was 0.26% (± 0.43%; mean ± SD). Data from each of the indicated patients and a representative healthy control are shown. Numbers in each quadrant are the percentages of total cells.