BTLA and neuroblastoma: The existence of the DC–NK axis in NB was further strengthened by the identification of the 16 gene DC (THBD, AXL, CX3CR1, FOS, GZMK, IL18R1, MEF2C, PRF1, SIGIRR, SYK, BAGE, BIRC5, CDK1, CT45A, PBK, and TTK) and 8 gene NK (NCR1, BTLA, CD7, CD160, CD247, GZMM, KLRC1, and KLRC2) cell signatures.