Analysis of published R338L-FIX assay results using the field study calculator. Published FIX:C SynthASil assay data for 4 R338L-FIX gene therapy patient samples were used as input (A) in the field study calculator, and the predicted values for (B) ACTIN-FSL, (C) CK Prest, (D) PTT Automate, and (E) ROX FIX were compared with the matching assay-measured values. The average CV (%) between measured and predicted values is shown in (F).