Embryonic stem cells (ESC) are primitive undifferentiated cells derived either from the ICM of Day 5 Blastocyst OR the genital ridge 5-9weeke post-fertilization. They can be cultured and induced to differentiate into all types of cells including Cardiomyocytes, Hepatocytes, Pancreatic cells, neural cells etc.They have a wide range of applications including:Cell therapies, Gene regulation, Developmental studies and testing drugs for safety. There are some obstacles to cell therapies which must be overcome before starting clinical trials.