KRAS and lung adenocarcinoma: Combined with symptoms, imaging examination and pathological findings, the patient was clinically diagnosed as left lung adenocarcinoma (cT4N2M1c, stage IVb, KRAS+, EGFR-, ALK-, ROS1-, PD-L1-), multiple metastases in both lungs, bone metastases, and clear cell carcinoma of the left kidney (cT1bN0M0 stage I, PD-L1-).