Dampened X-chromosomes in human pluripotent stem cells: dampening or erasure of X-upregulation?

The recent report of X-chromosome dampening in human preimplantation embryos remains controversial. Subsequently, Sahakyan et al. found evidence of X-chromosome dampening in human naïve pluripotent stem cells (hPSCs) as well. Here, we discuss whether X-dampening reported in hPSCs truly reflects the dampening of X-chromosomes or it is a consequence of the erasure of X-chromosome upregulation.