To test whether paclitaxel, doxorubicin and gemcitabine drugs that are frequently applied in combination therapy can affect ABC transporter transcription, 3D co-cultures were created using primary human lung fibroblasts (NHLF) and the adenocarcinoma cell line A549 or the squamous cell carcinoma cell line H520. Here, ABCG2 is linked to squamous cell carcinoma.