Although epigenetic drugs had a stimulatory effect on [177Lu]Lu-DOTA-TATE uptake in most MTT tumors, non-responders to the treatment occurred, indicating that the individual efficacy depends on various experimental and animal-specific conditions, which might include biodistribution and pharmacokinetics of the epigenetic drug after intraperitoneal injection, heterogeneity in vascularization and perfusion of tumors, heterogeneity in basal SSTR2 content of tumors, and drug-related toxicity attenuating radiotracer uptake in tumor cells. The gene discussed is SSTR2; the disease is neoplasm.