From a Persian queen’s brutal mastectomy in the fifth century BC to the 19th century recipients of primitive chemotherapy, humans have long tried to beat cancer. But even as we routed other scourges like cholera and tuberculosis, launched ambitious public health campaigns, exposed the dangers of chemicals like nicotine, and survived ever more rigorous treatment regimens, cancer remained as deadly and mysterious as ever. Cancer physician and researcher Siddhartha Mukherjee, author of The Emperor of all Maladies: A Biography of Cancer, visited Zócalo to tell stories of a disease we’ve lived with, died from, and tried to conquer for thousands of years—and what it was like to write about it.