There have been several modifications to the original SAGE technique aimed at addressing the potential pitfalls. MicroSAGE and SAGE-Lite were developed to allow lower amounts of starting mRNA to be used allow significantly smaller amounts of human or animal specimens to be examined (76, 78) , whereas LongSAGE and Robust-LongSAGE were developed to improve tag or gene mapping by generating tags of 21 base pairs as opposed to 14 (35, 85, 105) .