CD274 and small cell lung carcinoma: SCLC immunogenicity has been evoked by (i) the expression of PD-1/PD-L1 detected in SCLC samples, especially in immune cells present in the stroma [11]; (ii) its strict correlation with smoking exposure, causing non-synonymous mutations therefore turning out in high tumor mutational burden (TMB) [12]; (iii) auto-antibodies cross-reacting with the neuronal antigen present in 16% of SCLC patients, leading to auto-immune paraneoplastic syndromes in approximately 5% of the cases [13,14].