Embryonic Stem cells (ES) were discovered as the primary source of Pluripotent cells, but due to controversial ethical issues related to ES cells, scientists were forced to shift their focus to other sources of pluripotent cells. This made the emergence of the induced Pluripotent Stem (iPS) cells.
ES cells can be obtained from the blastocoel of the blastomere (developed zygote cells). While in case of iPS, somatic cells are engineered by inserting four fundamental genes such as OCT4, SOX2, NANOG, and LIN28 to make these cells behave as ES cells. These cells also have in similar the telomerase activity.
So in leighman’s view we can perceive that iPS cells are just a look alike of ES cells and nothing more. It is using the property of the ES cells without obtaining the same from a human embryo. But the main question arises here where it tells was this discovery as essential as the need of the people who are suffering from deadly disease and require the treatment of stem cells?
Many might differ in idea, but at the end of the day one can understand, that using iPS in place of ES cells is nothing but preferring milk powder to milk. Not only a lot of resources have been wasted in such type of researches when the same could have been used to successfully implement ES cells into therapeutic use.
No denial can be confronted now to the development of the ES cells since they have received the licence from the FDA and what could have been achieved long ago in 2001, had to suffer a eight year delay.