Intriguingly, we found that BHLHE40 was highly expressed in cluster 2 (Fig. 2i), which is consistent with a previous study that reported BHLHE40+CD4+ T cells to have the ability to suppress colon cancer cells20, supporting the speculation of the tumor-suppressing function of cluster 2, which need further functional validation. The gene discussed is BHLHE40; the disease is neoplasm.