(3) Iron
While we need iron for oxygen transport and countless enzymatic reactions, excess free iron is highly reactive. It fuels the Fenton reaction, generating massive amounts of ROS that damage tissues, oxidize lipids, and promote widespread oxidative stress. Heme iron (from meat) is not the problem, as our bodies can carefully regulate the amount of heme iron in the body.
In contrast, our bodies cannot regulate non-heme iron, which is the form found in iron-fortified cereals, iron supplements, plant foods, and cast-iron cookware. When free iron accumulates beyond what our livers can safely store, the body needs to store it in another location.
Cancer locks up iron inside hollow shells, made of ferritin, that encapsulate up to 4,500 iron atoms in a non-reactive form.
Tumors frequently become specialized iron-sequestering vaults. Cancer cells dramatically upregulate ferritin and other iron-binding proteins, pulling excess iron out of circulation and locking it away inside the tumor microenvironment. This protects the rest of the body from the oxidative havoc that free iron would otherwise unleash.
The fact that cancer cells lock up iron into a safe vault contradicts the theory of mainstream medicine that cancer uses iron for growth. Rather it supports TST, since cancer stores iron for safekeeping, to ensure that it doesn’t participate in the Fenton reaction.
In TST, iron-rich tumors are not random defects — they represent the body’s strategy for isolating a metal it cannot fully excrete or store safely elsewhere.
The strong association between iron overload and many cancers is therefore evidence that the body uses tumors as a last-resort compartment to store this toxic metal.
(4) Microplastics
Microplastics and nanoplastics represent one of the most insidious modern toxins the body must contend with. These tiny plastic particles have now infiltrated virtually every environment and every human tissue, including the brain. Because they are virtually indestructible and highly inflammatory, the body faces a serious challenge: it cannot easily break them down or excrete them.
When the primary detoxification systems become overwhelmed, the body once again demonstrates its brilliance by creating specialized containment sites.
Cancer cells upregulate macropinocytosis to internalize microplastics. Normal cells have limited endocytic activity, while many cancer cells dramatically increase macropinocytosis — a bulk “drinking” process driven by membrane ruffling. This allows them to engulf large volumes of extracellular material, resulting in significantly higher uptake and retention of microplastics and nanoplastics compared to normal cells.
Tumors, particularly in organs like the brain, lungs, and colon, actively sequester microplastics and nanoplastics. Studies show significantly higher concentrations of these particles inside tumor tissue compared to surrounding healthy tissue.
Cancer cells appear to engulf and isolate these foreign particles within their microenvironments, preventing them from circulating freely and causing even wider systemic damage.
In the Toxin Sequestration Theory, this is not random accumulation — it is the body intelligently using tumors as “particle vaults” to wall off these persistent invaders.
The presence of microplastics in tumors is therefore not evidence that cancer “causes” the problem, but rather proof that the body is doing everything in its power to contain a toxin it was never designed to handle.
(5) Mycotoxins
Mycotoxins — the toxic compounds produced by molds — are among the most potent natural toxins humans encounter.
When mold-contaminated foods, water-damaged buildings, or chronic fungal overgrowth overwhelm the liver and other primary detoxification pathways, the body faces a serious accumulation problem.
These toxins are highly inflammatory, immunosuppressive, and difficult to eliminate completely. In response, the brilliant body once again turns to its last-resort strategy.
Cancer cells pull in and store mycotoxins by upregulating their macropinocytosis (bulk endocytosis). Once inside, mycotoxins accumulate in endosomes and lysosomes, where the tumor upregulates antioxidant and detox enzymes to mitigate the resulting ROS. This allows the tumor to act as a sequestration compartment, isolating both the persistent mycotoxins and the oxidative stress they generate.