However, a special effect of chemoimmunotherapy is that it blunts the predictive significance of biomarkers relevant for IO monotherapy; for example, a higher PD-L1 expression, a higher TMB, and presence of KRAS mutations predict a better outcome of NSCLC patients treated with IO monotherapy but not chemoimmunotherapy [21,22,23,24]. The gene discussed is KRAS; the disease is non-small cell lung carcinoma.