ESR1 and cancer: As shown in Table 3, compared to “HER2+ subtype cancers" (HER2+, ER–, PR–), mPRα-HiEx rate and average levels of mPRα expression (59.26%, 1.41±0.11) were reduced among those with triple negative breast cancers (50%, 1.28±0.12), and further reduced among those with “ER+ subtype cancers" (35.00%, 1.08±0.07).