Differences in GIRK expression in three squamous carcinoma cell lines. Top panel: GIRK1 was expressed in all three squamous cell lines, H2170, H226, and H520. Middle panel: GIRK2 is only expressed in H520 cell line, but not in H2170 or H226. GIRK4 was expressed in all three squamous cell lines, H2170, H226, and H520. Bottom panel: Cyclophilin, used as a positive reaction control was seen in all samples. For all gene expression experiments, negative control reactions were performed and found to be negative. The bands on the agarose gels were consistent with the expected sizes: GIRK1-441 bp; GIRK2-438 bp; GIRK4-401 bp; cyclophilin-216 bp; M-100 bp.