Although many reports have described NK-cell activation mediated via EAT-2-induced signals through the SLAMF7–SLAMF7 interaction, the adaptor protein-mediated signaling pathway downstream of SLAMF7 in MM cells remains unclear due to the deficiencies of both SAP and EAT-2 in these cells [69,78]. This evidence concerns the gene SH2D1B and Miyoshi myopathy.