T helper 17 (T-h17) cells have essential functions in autoimmune diseases and inflammation belonging to a group of T cells. To maintain self-tolerance and prevent autoimmune responses, Regulatory T cells (iTregs) are used to function suppressively. Proteins are one of the important biomolecules forming the functional and structural entity of a living cell. To determine the set of proteins expressed by a cell, tissue, or organism at a certain time mass spectrometry-based quantitative proteomics can be used. The immune system protects the body against harmful pathogens and tumors providing self-tolerance. T-helper cells play critical roles in controlling immune reactions as they are the major components of the adaptive system. The label-free quantitative proteomics which is an advanced technology is utilized to identify the proteomes of Th17 and iTreg cells. This technology has generated a resource that is used to identify over 4000 proteins expressed in Th17 and iTreg