The study by Marr et al. examines the incidence and risks of mold infections in hematopoietic stem cell transplant (HSCT) recipients at the Fred Hutchinson Cancer Research Center from 1985 to 1999. The results show an increase in invasive aspergillosis, particularly in allograft recipients after 1992, and a rise in infections caused by non-fumigatus Aspergillus species, Fusarium species, and Zygomycetes, especially in patients who received multiple transplants. Infections with Scedosporium species were common in neutropenic patients, while Zygomycetes infections typically occurred later, coinciding with graft-versus-host disease. The overall 1-year survival rate for all mold infections was poor, around 20%. The study highlights the changing epidemiology of mold infections, emphasizing the increasing importance of amphotericin B-resistant organisms and the differences in risk and outcome among various filamentous fungi.The study by Marr et al. examines the incidence and risks of mold infections in hematopoietic stem cell transplant (HSCT) recipients at the Fred Hutchinson Cancer Research Center from 1985 to 1999. The results show an increase in invasive aspergillosis, particularly in allograft recipients after 1992, and a rise in infections caused by non-fumigatus Aspergillus species, Fusarium species, and Zygomycetes, especially in patients who received multiple transplants. Infections with Scedosporium species were common in neutropenic patients, while Zygomycetes infections typically occurred later, coinciding with graft-versus-host disease. The overall 1-year survival rate for all mold infections was poor, around 20%. The study highlights the changing epidemiology of mold infections, emphasizing the increasing importance of amphotericin B-resistant organisms and the differences in risk and outcome among various filamentous fungi.