The current study was performed to investigate the major feedback mechanisms that emerged as a result of exposure of NSCLC to osimertinib, identifying the occurrence of an adaptive response due to the activation of AXL, which binds to the HER family proteins EGFR and HER3 through a negative feedback loop involving the suppression of SPRY4. The gene discussed is SPRY4; the disease is non-small cell lung carcinoma.