NFKB1 and small cell lung carcinoma: The nucleotide‐binding oligomerization domain‐like receptor family pyrin domain‐containing 6 has a critical function in small cell lung cancer (SCLC) metastasis, where it acts on TAMs via SCLC‐secreted exosomes, inducing the activation of NF‐κB signaling and promoting M2 polarization.100