Inversion efficiencies of the loxF8 locus in HEK293T cells 72 h after transfection with D7 and D7-ZF, quantified by qPCR. The assay was performed three times ( n = 3, biologically independent samples, plotted as dots). The bar graphs represent mean values, and the error bars indicate the standard deviation from the mean. Statistical relevance was assessed using an unpaired two-sided t -test. P values are indicated.