293s vs HEK/293 cells - (Feb/18/2014 )

Hi, anyone knows what's the difference between 293s and HEK/293 cells?
Thanks!

I am not asking the 293t cells with T-antigen.

HEK293 are the original cell line, however, as it has subsequently been found that these are not actually derived from the kidney, but instead are more like neural crest cells, some people refer to them as purely 293.