Update README.md

README.md

@@ -78,7 +78,8 @@ Overall, the numbers of negatives and positives in this data set were balanced w
 In addition, 805 approved drugs from DrugBank that were not involved in the training set, and 664 Ames strong positive samples 
 from DGM/NIHS were built as an external validation set.
 
-We downloaded the [original dataset](https://github.com/Louchaofeng/Ames-mutagenicity-optimization) which was uploaded in 2023.
+This is a mirror of the [official Github repo](https://github.com/Louchaofeng/Ames-mutagenicity-optimization) where the dataset was uploaded in 2023.
+
 
 ## Data splits
 Here we have used the Realistic Split method described in [(Martin et al., 2018)](https://doi.org/10.1021/acs.jcim.7b00166) to split the MutagenLou2023 dataset.