List of ER+her2+ cell lines from SABCS poster presenter (UCLA researcher)
 

In regards to your question at SABCS regarding ER+ HER2+ cell lines, they include:

UACC-732
SUM-190
ZR-75-30
BT-474
EFM-192A
HCC-1419
HCC-2218
MDA-MB-361
UACC-893
HCC-202
UACC-812

This should help all those trying to read the literature re preclinical work looking at the best combination of treatments for this subtype of her2+ bc. As I have previously opined, there are probably many subtypes of ER+her2+ bc, so the more types of cell lines, the more likely some may approximate what occurs in vivo making it more likely a good treatment or combo of treatments is identified.

Hope this is helpful and makes you more comfortable reading the more basic research articles. It really is not rocket-science with information like this and a bit of translation of complex terms/procedures (FISH, rtPCR, etc)