A team of Singaporean scientists have identified a gene responsible for lung cancer, the Agency for Science, Technology and Research said on Friday. A small number of cells, known as cancer stem cells or tumor- initiating cells (TIC), are responsible for the promotion of tumor growth. The team of scientists found a marker, known as CD166, to identify these cells, it said. The team, led by Bing Lim, associate director of cancer stem cell biology at the Genome Institute of Singapore, and Elaine Lim, medical oncologist affiliated with Tan Tock Seng Hospital and National Cancer Center Singapore, did more genomic study of the TICs, and discovered several genes that were important for the growth of cancer cells. The scientists discovered that in abnormal instances when the level of a metabolic enzyme known as glycine decarboxylase rises significantly, it causes changes in the behavior of the cell, making it cancerous. The glycine decarboxylase is a normal occurring enzyme in cells, present in small quantities. The finding is reported in the online advance issue of Cell on Jan. 5 and is believed to be a huge step towards finding a cure for the disease.