Corrigendum: A Chinese medicine formula (kunbixiao granule) for female rheumatoid arthritis: Study protocol for a double-blind, randomized, placebo-controlled trial - Wan, Yingying; Yang, Jiaxi; Ma, Tianyue; Wang, Wenqian; Wang, Haonan; Sun, Wenting; Ye, Wanting; Yang, Lin; Kou, Qiuai (Frontiers in Pharmacology, 2022)