Combined use of serum ferritin and KL-6 levels as biomarkers for predicting COVID-19 severity Authors Yuko Kitagawa (ORCID: https://orcid.org/0000-0001-6469-2155) Akinori Kimura (ORCID: https://orcid.org/0000-0002-4933-2132) Hirofumi Kamata (ORCID: https://orcid.org/0000-0002-1807-5911) Shuhei Azekawa (ORCID: https://orcid.org/0000-0001-5538-6324) Takanori Kanai∥ (ORCID: https://orcid.org/0000-0002-1466-4532) Yukinori Okada (ORCID: https://orcid.org/0000-0002-0311-8472) Makoto Ishii (ORCID: https://orcid.org/0000-0003-4396-1664) Seishi Ogawa (ORCID: https://orcid.org/0000-0002-7778-5374) Ryuji Koike (ORCID: https://orcid.org/0000-0001-5647-8159) Katsunori Masaki (ORCID: https://orcid.org/0000-0003-0909-9409) Mayuko Watase (ORCID: https://orcid.org/0000-0003-3557-5173) Takanori Asakura (ORCID: https://orcid.org/0000-0003-3122-6937) Ho Namkoong (ORCID: https://orcid.org/0000-0001-6181-4284) Hiromu Tanaka (ORCID: https://orcid.org/0000-0002-5299-3978) Kensuke Nakagawara (ORCID: https://orcid.org/0000-0001-5249-6923) Takahiro Fukushima Shotaro Chubachi (ORCID: https://orcid.org/0000-0002-5046-3762) Satoru Miyano (ORCID: https://orcid.org/0000-0002-1753-6616) Kaori Sakurai Seiya Imoto (ORCID: https://orcid.org/0000-0002-2989-308X) Erika Toya Shiro Otake Naoki Hasegawa Koichi Fukunaga Institutions Tokyo Medical and Dental University (JP) Keio University (JP) Kyoto University (JP) Keio University Hospital (JP) RIKEN Center for Integrative Medical Sciences (JP) Kitasato Institute Hospital (JP) Nagoya University (JP) The University of Tokyo (JP) Funders Japan Agency for Medical Research and Development Japan Science and Technology Corporation Ministry of Health, Labour and Welfare Explore the Global Research Space Interactive Map