Here, we present a refined and detailed surgical method in which murine tumour cells [Lewis lung carcinoma (LLC), alveogenic lung carcinoma (CMT), or Kras/Trp53‐KP mutant cells] were injected directly into the left lung lobe of C57BL/6 mice, or, alternatively, adenoviral‐Cre or adenoviral‐FlpO was administered directly into the left lung lobe of KrasLSL‐G12D;Trp53fl/fl or KrasFSF‐G12D;Trp53frt/frt (KP) mice, respectively. The gene discussed is KRAS; the disease is Carcinoma, Lewis Lung.