AKT1 and non-small cell lung carcinoma: The H1650/R and H1975/R cells were exposed to Shikonin for 48 h and the result showed that the expressions of p-PI3K, p-Akt were down-regulated compared with control group in H1650/R and H1975/R cells (Figure 3B), indicating that Shikonin inhibited cell viability and induced apoptosis of afatinib-resistant NSCLC cells via negative regulation of PI3K/Akt signaling pathway.