Despite the existence of a large number of QSRR studies, most of them use small data sets (less than 1000 compounds) and usually do not answer whether the obtained results will be reproducible if the data set is slightly changed. For example, in Ref. , the authors make some qualitative conclusions about retention based on a set of MD chosen using sequential selection. The authors do not study whether the MD selection procedure is reproducible and whether the same MD set will be chosen if the data set is slightly distorted. If a method is unstable to insignificant changes in the data set and random factors, it may lead to misleading conclusions.