Tumor Microenvironment: Cancer cells often thrive in a more acidic environment compared to normal cells. This is partly due to the metabolic processes of cancer cells, which can produce lactic acid and other acidic byproducts. The acidic microenvironment can promote tumor growth and invasion.
Many tumors exhibit an acidic microenvironment. This is largely due to the high rate of glycolysis (often referred to as the Warburg effect), even in the presence of oxygen, leading to lactate production. Acidification is thought to promote invasion, metastasis, and resistance to certain chemotherapies.
The body maintains a relatively stable pH in the blood (around 7.4). However, the pH of tissues can vary, and tumors can exhibit a lower pH.

-normal tissues have a higher extracellular pH than intracellular pH, in cancer is exactly the opposite. (inversion of the pH gradient)

Cancer cells often overexpress proton pumps (such as V-ATPase) and transporters that actively extrude protons (H⁺) to maintain an intracellular pH conducive to their growth.
Inhibiting these pumps can lead to intracellular acidification and potentially induce apoptosis or render cancer cells more vulnerable to other treatments.