We wish to retract the article titled “IL-21/IL-21R Signaling Aggravated Respiratory Inflammation Induced by Intracellular Bacteria through Regulation of CD4+ T Cell Subset Responses” by Wenhao Niu, Yueyue Xu, Xiaoyu Zha, Jiajia Zeng, Sai Qiao, Shuaini Yang, Hong Zhang, Lu Tan, Lida Sun, Gaoju Pang, Tengli Liu, Huili Zhao, Ningbo Zheng, Yongci Zhang, and Hong Bai, The Journal of Immunology, 2021, 206: 1586–1596.

Figs. 1E and 6C of the above manuscript contain images duplicated from Fig. 2C of our article titled “IL-27/IL-27R Mediates Protective Immunity against Chlamydial Infection by Suppressing Excessive Th17 Responses and Reducing Neutrophil Inflammation.” There was an additional duplication in the rIL-21 samples between days 7 and 14 in Fig. 6C. We were unable to unambiguously resolve these duplications. We deeply apologize to our colleagues and the scientific community for any inconvenience this may have caused.

All authors agree with this retraction.

Wenhao Niu

Yueyue Xu

Xiaoyu Zha

Jiajia Zeng

Sai Qiao

Shuaini Yang

Hong Zhang

Lu Tan

Lida Sun

Gaoju Pang

Tengli Liu

Huili Zhao

Ningbo Zheng

Yongci Zhang

Hong Bai

Tianjin Medical University

Tianjin, People’s Republic of China