Accordingly, we chose 1-2 genes from each group for validation analysis as follows: 1) Drug resistance related genes: ABCC3 product is involved in multi-drug resistance which provides protection from chemotherapeutic agents in various cancer cell subpopulations [45], GALC encodes the glucosylceramide enzyme, which is involved in mechanism of drug resistance in cancer cells [46] and CYP3A5 which encodes for a protein that catalyzes reactions involved in drug metabolism [47]. Here, GALC is linked to cancer.