To our knowledge, we report the first case of a pseudoprogression with durable complete response that occurred spontaneously after an unequivocal progression under a standard chemoimmunotherapy regimen in a patient with a PD-L1-negative, TMB-low, KEAP1/STK11 co-mutated NSCLC. The gene discussed is KEAP1; the disease is non-small cell lung carcinoma.