mTOR or mammalian target of rapamycin is an evolutionarily conserved serine-threonine kinase and is composed of 2549 amino acids that acts as intracellular kinase and controls the production of proteins through effects on the machinery of mRNA translation and also plays a role in cell growth and metabolism. mTOR is a critical regulator of immune function due to its role in sensing and integrating cues from the immune microenvironment. mTOR plays a role in regulating diverse immune cells, including neutrophils, mast cells, natural killer cells, γδ T cells, macrophages, dendritic cells (DCs), T cells, and B cells. mTOR pathway is an important regulator of cell growth and proliferation and mTOR dysregulation can cause various cancers. mTOR's role as a regulator of many cell processes and its potential as a therapeutic target has opened up treatment possibilities in several types of cancer. An active mTOR coordinates a response in cell growth directly through its effects on cell cycle regulators and indirectly by sustaining nutrient supply into the cell through the production of nutrients.