Masoretic Text
The postdiluvian Cainan does not appear in the (Proto-)Masoretic Text, the most common Hebrew version of Genesis, where Arpachshad is noted as the father of Salah. He is also omitted from the writings of the Jewish historian Josephus. Early Christian writers Irenaeus and Eusebius of Caesarea believed his presence to be an error mainly on the basis of his omission from the (Proto-)Masoretic Text, and many subsequent interpreters followed this. However Helen Jacobus has argued that the omission from the Masoretic text is deliberate.