ESR1 and neoplasm: In a multivariate random effects analysis, the effect of FKBPL on BCSS remained significant after adjusting for other known prognostic factors, including; tumor size, grade, nodal status, ER and PR status with time dependent covariates (HR = 1.25, 95% CI 1.07–1.45, p = 0.004), and after the addition of Her2 status as a time dependent covariate (HR = 1.21, 95% CI 1.06–1.42, p = 0.02).