Necela et al. studied the association between FOLR1 and HER2 expression by analyzing the distribution of FOLR1 mRNA expression using RNA-sequence data from multiple patient cohorts across three breast cancer subtypes: estrogen receptor-positive (ER+), HER2-positive (HER2+), and triple-negative (TNBC) tumors. The gene discussed is ESR1; the disease is breast carcinoma.