GI-101A is an estrogen-receptor and EGFR-positive, basal-like low metastatic cell line derived from a primary infiltrating ductile breast tumor [20] and its counterpart GI-LM2 is a highly metastatic variant that was isolated from repeated lung metastasis of GI-101A (Additional file 2: Figure S1C) [17]. The gene discussed is ESR1; the disease is breast neoplasm.