Evaluation of DDR1, TEK, and FES mutations in Ba/F3 WEHI independence assay. Ba/F3 cells were transfected with constructs expressing wild-type or mutant DDR1 (A), TEK (B), or FES (C). Following 4 weeks of neomycin selection, stably transfected cells were washed with WEHI-free media and plated in media containing 10-fold serial dilutions of IL-3, ranging from 1 ng/mL to 10⁻⁵ ng/mL. Cells were subjected to an MTS assay at day 3 after plating for determination of total viable cells. Values represent mean plus or minus SEM.