PDCD1LG2 and small cell lung carcinoma: In SCLC, B7H3 expression is high and remarkably consistent across the 4 distinct molecular subtypes and is not correlated with PD-L1 expression or T cells, but it has been reported a strong correlation with some immune checkpoint genes, including HAVCR2/TIM3, CD86, and PDCD1LG2/PD-L2, as well as M2 macrophages [36].