BCL6 and neoplasm: Specifically, a polarized Tfh cell distribution within GC as seen in tonsils was missing (Supplementary Figure 6) while a less structured clustering of Tfh cells was evident in areas characterized by sequestration of BCL6 positive cells (Figure 5D), a profile associated with the frequency of tumor cells inferred from the VAF of tumor specific mutations (RHOA G17V VAF and IDH2 VAF) (Table 4 and Supplementary Figure 6).