This is subsequently supported by data from an independent dataset, GDSC (Genomics of Drug Sensitivity in Cancer; https://www.cancerrxgene.org/), showing that the most Rac inhibitor-sensitive HNSCC cell line, HSC4, was a RAC1-amp HNSCC cell line with outlier sensitivity to EHT-1864, another Rac inhibitor in the GDSC2-HNSCC dataset. Here, RAC1 is linked to head and neck squamous cell carcinoma.