It's noticeable that the enrichment levels in the pathways of "platinum drug resistance", "EGFR tyrosine inhibitor resistance" and "ABC transporters" were down-regulated after KDM1A knockdown (Figure S3B), indicating that KDM1A may mediate the multidrug resistance (MDR) of ATC cells, which is thought to be a pivotal reason for the failure of chemotherapy in many cancers 53. Here, ABCG2 is linked to cancer.