Table 3. Probability of Interlaboratory and Intercytokine Differences in Recovery of Cytokines across Assays.

	interlaboratory
	IL-1β			IL-6		intercytokine
assay	86/552	86/680	assay calibrators	89/548	assay calibrators	IL-1β	IL-6
BioSource	<0.0001a	NA	<0.0001	0.280	0.007	<0.0001	0.005
Endogen	NAb	NA	NA	<0.0001	0.023	<0.0001	<0.0001
Quantikine	<0.0001	<0.0001	0.018	0.054	<0.0001	<0.0001	<0.0001
QuantiGlo	<0.0001	0.003	<0.0001	0.465	0.002	<0.0001	<0.0001
Beadlyte Luminex	0.552	0.001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001
in-house Luminex	<0.0001	<0.0001	0.014	<0.0001	0.199	0.054	<0.0001
MSD Small Spot	0.094	0.049	0.028	0.814	0.049	<0.0001	<0.0001

^aP < 0.01 indicates that the % recovery was different between laboratories or between cytokines (Mann−Whitney, Kruskal−Wallis).

^bNA = not applicable; the analysis was not applicable when <2 laboratories provided data from the same kit.