Figure 1From: Plasma osteopontin levels in patients with head and neck cancer and cervix cancer are critically dependent on the choice of ELISA systemOsteopontin levels in individual plasma samples obtained from cervix or head and neck cancer patients undergoing radiotherapy. All samples were measured with two different ELISA systems, a newly introduced assay (A) and an older assay (B) marketed under two different names (see text). The results of both assays were significantly correlated (p < 0.05, Spearman rank test). For clarity, two data points with values of 80.5 and 189.5 ng/ml for assay A are not displayed.Back to article page