Figure 6c–e shows that HSP90AA1, RAC1 and CDKN1A expression levels were clearly related to the prognosis of lung adenocarcinoma (LUAD) or lung squamous cell carcinoma (LUSC) patients, which indicated that high expression of the three genes was significantly associated with a lower rate of overall survival. The gene discussed is CDKN1A; the disease is squamous cell lung carcinoma.