In addition, the results showed that five of the six mRNAs defined by the Lasso Cox regression model (RDH16, SPC25, SPC24, SCUBE3, and DGAT2) showed positive coefficients, indicating that these mRNAs were closely related to the prognostic risk of Her2-positive breast cancer patients, and higher expression corresponded to shorter OS. Here, RDH16 is linked to breast cancer.