POU2F3 and small cell lung carcinoma: Further analyses have also identified two distinct subtypes within SCLC-I: NE-SCLC-I, which retains some NE characteristics and is associated with higher T-effector cell infiltration and potential ICI responsiveness; and Non-NE-SCLC-I, which exhibits POU2F3 expression, with limited benefit from immunotherapy [49].