A Cell viability curve for the SAS/-IR and TW2.6/-IR cell line at 48 h of treatment with dose-dependent of cisplatin. B BTK-KD cells exhibited slower area closure than WT cells in the in vitro scratch wound cell migration assay after 48 h. C BTK-knockdown significantly decreased colony-forming abilities. D The quantitative data of the two types of cells. E, F Immunofluorescence staining images showing the BTK expression, E-cadherin, and vimentin in SAS-IR WT and SAS-IR cells transfected with shBTK. DAPI, nuclear staining. All assays were performed at least twice in triplicate and expressed as mean ± SD. *p < 0.05, **p < 0.01.