X inactivation starts at the X-inactivation center(XIC) and spreads throughout the chromosomes.
染色体失活开始于X染色体失活中心（XIC），然后传播到整条染色体。
2
X inactivation starts at the X inactivation center (XIC) and spreads throughout the chromosome.
失活开始于XIC，然后传播到整条染色体。
3
The protective effect of hypo xic RT on normal tissues has been proved. However, there was not an affirmative answer whether hypoxic RT had any protective effect on tumor.