We are a dedicated group of specialists for adults and children in the care of allergic and immunologic disorders.

Our Mission

Our mission is to provide the highest quality care possible. Attentive to your individual needs, we strive to build a patient-physician relationship based on our core values of compassion, integrity, and professionalism.  We are truly committed to providing you excellent service, and to helping you lead and maintain a healthier life. We welcome the opportunity to serve you.

Our Physicians

Our physicians are certified by the American Board of Allergy & Immunology, or the American Board of Internal Medicine, or the American Board of Pediatrics.


Kenneth Lien, MD

Board-Certified, Allergy and Immunology

Kenneth Lien, MD

Kenneth Lien, MD is a graduate of Yale University, and the University of Chicago-Pritzker School of Medicine. He completed internship and residency training in Internal Medicine at Kaiser Foundation Hospital, in Oakland. He completed fellowship training in Allergy and Immunology at the University of Medicine and Dentistry-UMDNJ, New Jersey. He has been in professional practice since 2005, and is affiliated with Sutter Health Eden Medical Center. Previously, he worked as an allergist for Kaiser Permanente, where he also served as Chief of Allergy for the Greater Southern Alameda Area. He is a member of the American College of Allergy, Asthma & Immunology (ACAAI) and the American Academy of Allergy, Asthma & Immunology (AAAAI). Kenneth grew up in Southern California, and has called the Bay Area home since 1998. In his free time, Kenneth enjoys cycling and running down the California coast, watching re-runs of Anthony Bourdain, and traveling. He is board-certified in Allergy and Immunology.


Yunji Lee, NP

Board-Certified, Pediatric Nursing

Yunji Lee, NP

Yunji Lee is a board-certified Pediatric Nurse Practitioner (CPNP). She received her Bachelor of Arts in Molecular Cell Biology (Immunology Emphasis) from University of California, Berkeley in 1998. She has extensive research experience in Immunology having worked at Trellis Bioscience, J. David Gladstone Institutes, and Roche. After working in the biotech industry, she felt a desire to go back to school to become a pediatric nurse practitioner. She then received her Registered Nursing and Master of Science in Nursing (PNP specialty) degrees from Yale University School of Nursing in 2008. Prior to joining in this office in 2014, she worked at a private practice in Sacramento and a community health clinic in Hayward. In her spare time, Yunji enjoys cooking, traveling, hiking, and wine tasting. She is fluent in Korean.

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20400 Lake Chabot Road
Suite 304
Castro Valley, CA  94546
phone: 510.537.0700
fax: 510.537.7795