CTLA4 and small cell lung carcinoma: Many approaches to overcome the results obtained from this two-drug combination had failed until the advent of ICIs: the addition of anti-PD-L1 (atezolizumab, durvalumab) but not anti-CTLA4 to standard CT was proven to prolong the overall survival by around two months with respect to CT alone, and more importantly for the first time in SCLC it allowed patients to reach a survival rate of 17.6% and 12% at 3 years and 5 years, respectively [9,10,18,20,21,22].