Interesting sequence in Genesis 4-6. In Genesis 4:17-24 the genealogy of Cain, or
sons of men, is listed. In the next verse (Genesis 4:25) the genealogy of Adam, or
sons of God, begins and continues for all of chapter 5. The lineage of the sons of God begins with the phrase "men began to all upon the name YHWH", which distinguishes them from the sons of men who didn't.
And Adam knew his wife again; and she bare a son, and called his name Seth: For God, said she, hath appointed me another seed instead of Abel, whom Cain slew. And to Seth, to him also there was born a son; and he called his name Enos: then men began to call upon the name YHWH. This is the book of the generations of Adam. In the day that God created man, in the likeness of God made he him; Genesis 4:25-26, 5:1
The book of the generations of the sons of God ends with Noah in Genesis 5:32. Then in the next 2 verses it says that the sons of God took daughters of men, which suggests the sons of men, ie the lineage of Cain.
And Noah was five hundred years old: and Noah begat Shem, Ham, and Japheth. And it came to pass, when men began to multiply on the face of the earth, and daughters were born unto them, That the sons of God saw the daughters of men that they were fair; and they took them wives of all which they chose. Genesis 5:32-6:2