Next, the percentage of children of library A predicting undesirable high affinities to human VKORC1 were investigated. Results showed that only 10.2 % of the 12037 children predicted human-VKORC1 docking-scores equal or lower than those in rats (Figure , blue spheres and blue horizontal continuous line). These results suggested those children should be excluded for further work because of the risk of being toxic to humans. In this work, we have chosen a rathuman docking-score differential threshold of -25 to be strict in reducing the possibilities of any undesirable interference with human VKORC1 (Figure , blue horizontal dashed line). Such threshold eliminated 93.7 % of the non-toxic children resulting in library B. Library B contained 747 non-toxic children with maximal affinities to rat VKORC1 (Figure , red points) and minimal to human VKORC1. Different rat -human thresholds for children elimination could be varied for any future work.