Part of trastuzumab's effectiveness depends on ADCC, where the fragment crystallizable (Fc) region of trastuzumab interacts with FcγRIIIA (CD16) on natural killer (NK) cells, leading to NK cell activation, cytokine production, and tumor cell lysis through perforin/granzyme B-mediated killing [7–10]. This evidence concerns the gene FCGR3A and neoplasm.