Moreover, in our previously published cohort of 40 FFPE ACC samples (Liang et al., 2020), PLK1 mRNA levels were significantly correlated with several known anti-cancer drug targets, i.e. negatively with AKT2, BIRC5, CDC25A, CDK2, CDK5, CDK7, CDK8, ESR1, FLT1, and GRB2 and positively with HDCA1, HDCA2, HDCA4, HRAS, KIT, NFKB1PIK, PARP1, PIK3C2A, PLK4, TOP2A, TOP2B,and TXN. The strongest and/or most biologically relevant correlations are shown in Supplementary Fig. 3. This evidence concerns the gene GRB2 and cancer.