Autoimmune is a disease caused by imbalance of immunology and losing tolerance then causes autoimmunity to attack body tissues in organisms. This disease occurs when the self-antigens attached by adaptive immune response. This disease can be treated by stem cell therapy. Stem cell therapy is an assured alternative to autoimmune treatment. Stem cells that can differentiate or can change themselves into various cells according to the environment and function to replace the damaged body cells. This study aims to find out the utility of stem cell therapy as an innovation in the treatment of autoimmune diseases. Literasture review is the method used in this research and focus to discuss: 1) the body's immune system; 2) immune system disorders; 3) autoimmune disease mechanisms; and 4) Stem cell therapy as an alternative to autoimmune treatment. Through this paper, readers will know that there is one technology to use treating autoimmune diseases, stem cell therapy. The mechanism of utilisation of stem cell therapy varies with each type of autoimmune disease, but this therapy can also cause some side effects. Stem cell therapy repairs damaged cells and replaces them with new, more functional ones. Key words: autoimmune disease; stem cell therapy; human body; medication.

Polyethylene terephathalate (PET) is a type of plastic content that is commonly is difficult to degrade so that it has an impact on global environmental problems. Plastic waste pollution needs to be overcome by using environmentally friendly methods to accelerate the PET plastic biodegradation process. Biodegradation is the use of microorganism activity to decompose plastic compounds so as to reduce the volume of waste. Ideonella sakaiensis is a bacterium that produces PETase enzymes that play a role in degrading PET. This literature review aims to determine the potential of Ideonella sakaiensis encoding the PETase gene in degrading polyethylene terephathalate plastic waste by discussing three focus studies, namely: 1) the potential of Ideonella sakaiensis, 2) the characteristics of polyethylene terephathalate plastic waste, 3) the relationship between the PETase coding gene and the degradation of polyethylene plastic waste terephathalate. Biodegradation of plastic waste Polyethylene terephathalate using Ideonella sakaiensis which has the potential to degrade PET faster with the PETase enzyme. The biodegradation mechanism carried out involves the process of transforming the PETase coding gene from I. sakaiensis to Escherichia coli bacteria influenced by pH and the effectiveness of the PETase enzyme work until the use of harvested products interacts with Polyethylene terephathalate plastic waste, which decomposes plastic waste.ÂÂ