It turned out that Zhou Peiyuan actually had two sons, but because the eldest son, Zhou Hong, was frail and sickly from birth, the doctor said that the probability of Zhou Hong growing up safely was very low, so Zhou Peiyuan concealed Zhou Hong's existence from the outside world.
And indeed, as the doctor had said, Zhou Hong had already undergone two major surgeries by the age of seven, and by the age of twenty-eight, he had undergone dozens of major and minor surgeries, ultimately dying on the operating table.
Ye Nuannuan was actually Zhou Hong's living kidney storage. When Zhou Hong was sixteen, he was diagnosed with kidney failure, and Ye Nuannuan happened to be a match, so the Zhou Family arranged housing for Ye Nuannuan and her mother, taking care of their food and accommodations, all for the purpose of having Ye Nuannuan provide a kidney when Zhou Hong needed it.