GZMA and brucellosis: Four subclasses, including three effector CD8+ T‐cell subsets (CD8_eMemory, CD8_Effector_GNLY and CD8_Effector_GNLY_GZMK) and γδ T, may be the major contributors for eliminating the infected host cells in brucellosis patients (Figure S7B) as they simultaneously expressed multiple effector molecules (e.g., GZMA, GZMK, GNLY, CST7), especially for those at the acute stage (Figure S7C).