TBX21 and breast cancer: Our study using metaTF on scRNA‐seq breast cancer datasets found that CD8+ TEM cells could be divided into two clusters based on TF activity, with the ADRB2+ CD8+ TEM subset showing higher expression of activation and proliferation markers and genes related to immune responses, and validation experiments demonstrated that ADRB2+ CD8+ TEM cells respond to neuro‐related signals by activating key transcription factors such as BCL6, TBX21, and ATF3, along with their downstream targets.