The value is calculated by subtracting the lyso score of the 'from' compound from that of 'to' compound. In other words, if the lyso score distribution is shifted to the right, the transformation is accompanied by an increase in lysosomotropism. However, in none of the 'high-count' conversions shown in Fig. , the change in lyso score incidental to the transformations is in one direction only. The MMPA performed in this work intimates that there does not appear to be a dominant structural feature in the compound library under investigation that determines lysosomotropism.