Because the in vitro growth characteristics between STAT3-proficient and STAT3-deficient KPT organoids remained indistinguishable in the absence of exogenously added gp130 family cytokines (Figures S4C and S4D), we surmise that Stat3 deletion reduces the in vivo tumorigenicity rather than merely reducing tumor cell proliferation. The gene discussed is IL6ST; the disease is neoplasm.