Dr. Chen welcomes patients at: Genesis OB/GYN Northwest. Tucson, 6261 N. La Cholla Boulevard, Ste. 277. Oro Valley, 1521 E. Tangerine Road, Ste. 361. To arrange an appointment, please call 520-795-0771. Genesis OB/GYN Northwest - 6261 N. La Cholla Boulevard, Suite 277..