“…Results displayed in Fig 4 show as similar S/B ratios were obtained in the absence and in the presence of TNFα, p53, BSA, and hemoglobin, thus indicating that no significant interference of these non-target proteins occurred in the FGFR4 determination. However, a dramatic reduction in the S/B ratio was observed in the presence of 1 mg mL -1 human IgG (bar 6 in Fig 4) which can be attributed to the presence of human anti-mouse antibodies (HAMAs) or to the three immunoglobulin-like domains of FGFR4 [24] which would lead to significant errors in sandwich immunoassays using mouse monoclonal antibodies, since they can cross-link the capture and labeled antibodies in the absence of the analyte [25]. However, it is important to mention that the quantification of the target receptor at a 2,500 pg mL -1 level was still feasible in the presence of such high concentration of human IgG.…”