SDC1 and cholesteryl ester measurement: In the non‐CE, CE, and cured‐CE groups, the number of CD138‐positive plasma cells were 0.7 ± 1.0, 28.5 ± 30.4, and 1.3 ± 1.3 per 10 nonoverlapping random stromal areas within 3 months before or after the ERA (Table 2), and the difference among three groups was significant (p < .001).