"Ms. Fenneke Ge Joslin (née ter Weele) of 1900 Magnolia Street, Denver CO, died of lung cancer July 1, 2022 in Castleton, Virginia, where she happily spent her last few weeks visiting with extended family at the home of her brother and sister-in-law.

Fen was born July 29, 1943 in New Haven CT, the daughter of Carl Frits ter Weele and Margery Ethel Crane ter Weele. Fen lived the first two years of her life in Aruba, where her father, a Dutch army officer, commanded the island’s artillery installation. The family emigrated to the United States at the end of World War II, and lived in Cheshire CT, Weston CT, and Center Ossipee NH during Fen’s elementary and high school years. She graduated from Brewster Academy in Wolfeboro NH in 1960. Her Brewster yearbook shows that her classmates voted Fen “most studious,” “most likely to succeed,” and “most popular.” She graduated from Mount Holyoke College in 1964. She spent a two-year post-graduate medical internship at Boston’s Children’s Hospital under the guidance of Louis Kunkel, PhD, of Harvard University, focused on laboratory work in the fields of genetics and genomics.

Fen briefly married in her 20’s, and lived and worked in New York City. She eventually moved to her beloved Colorado, where she lived in Superior, then Boulder, then finally Denver. Fen loved the time she spent in laboratories, immersed in her groundbreaking research. Initially she focused on biochemistry and immunology, first at the University of Denver Teaching Hospital, and later at Somatogen, working on recombinant human hemoglobin for artificial blood. Later, she worked at Synergen and Amgen on novel stabilized interleukin 1 inhibitors and techniques for their synthesis and purification. Her groundbreaking work led to three patents for those inhibitors, filed in her name in the early 1990s. Now, years later, similar inhibitors are being used as treatments for rheumatoid arthritis and are being explored as antivirals and in connection to other autoimmune disorders; human interleukin-1 inhibitors have been implicated as the primary mediator of immune responses to mRNA vaccines.

Fen traveled frequently, especially with loved ones who cheered for her visits. She connected closely with five generations of family. Fen enthusiastically spent time with each person –reveling in the things they cared about right along with them. When a young godson loved trucks, Fen kept a lookout, and when a truck came along the street, together they ran outside, yelling and waving, both genuinely thrilled. She joined the kids’ table often, and she laughed with elders and babies alike, one-on-one. Fen’s bridge club in Colorado made up a card game called “Colorado Eights.” Fenny taught it to her growing nieces and nephews, and played it with them frequently for twenty years, in small and large and groups around kitchen tables. They taught it to friends, who taught it to other friends, spreading their beloved “Fenny-Penny’s” influence by bringing people together.

At home on Magnolia Street, Fen loved her friends and neighbors. She was particularly popular with small children, with whom she playfully exclaimed about drawings, games, photos, or wonderous items found out in nature. She was an ardent gardener and angler, enjoyed photography, was a fanatic bridge player, and did countless jigsaws, Sudokus and crosswords.

Fen is survived by three siblings, Jan C. ter Weele of Falmouth Maine, Alexander H. ter Weele of Castleton Virginia, and Margery K. Gagne of Lexington Virginia. Nephews and nieces surviving her include Kerst, France, Eric, André, and Carl—all ter Weele, and Charles and Katharine - both Gagne. Grand-nieces and nephews include Alex, Simonne, Maria, Jan, Jakob, Joshua, Kiki, Stafford, Everest, Nicolas, Lauren, Margot, David, Katharine, William, Peter, Emma, Eleanor, and Evelyn. One nephew, Rick Gagne, and one grandniece, Daniela Wine, preceded her in death. Fenneke loved them all dearly, and all adored her in return."