According to Genesis 5:
3 When Adam had lived 130 years, he had a son in his own likeness, in his own image; and he named him Seth. 4 After Seth was born, Adam lived 800 years and had other sons and daughters. 5 Altogether, Adam lived a total of 930 years, and then he died.
6 When Seth had lived 105 years, he became the father[b] of Enosh. 7 After he became the father of Enosh, Seth lived 807 years and had other sons and daughters. 8 Altogether, Seth lived a total of 912 years, and then he died.
If we continue reading, we see that we are descendants of Seth as his genealogy leads to the birth of Noah. God destroyed other families and spared only the house of Noah (8 people), from whom the earth was repopulated.
Adam->Seth-> ... ->Methuselah->Lamech->Noah->(Noah's Sons)-> .... ->Us
Genesis 7:23- Every living thing on the face of the earth was wiped out; people and animals and the creatures that move along the ground and the birds were wiped from the earth. Only Noah was left, and those with him in the ark
Cain's descendants and Seth's siblings' descendants were therefore wiped out.