In the microarray analysis, PRLR was down-regulated in HE steers (P < 0.001), whereas in RT-PCR analysis, expression of s-PRLR was not altered (P = 0.21) and expression of l-PRLR had a tendency to differ (P < 0.07) in HE vs. LE steers. This evidence concerns the gene PRLR and hereditary elliptocytosis.