Carlos Castro-González, “To Save 4000 Lives a Year”

Brilliant Spanish postdoc, Carlos Castro-González, goes to MIT’s “Magic Wand” lab, and joins a superb international team to address an important medical problem. Leuko, their startup, now has a device and software that can tell when cancer patients are becoming immuno-compromised. Leuko’s product has the potential of saving 4,000 lives and $1.5 billion every year by cutting in half opportunistic infections associated with chemotherapy. 


  • Carlos Castro-González bio.
  • What Leuko does.
  • How the company came about.
  • How Carlos became an unlikely entrepreneur.
  • MIT’s Martha Gray Lab, often called the “Magic Wand” lab building a new approach to applying technology to real-world medical problems.
  • What the device and software actually do.
  • Potential impact.
  • Who might pay for this product?
  • How much money and time will it take to get the product to market?
  • Licensing the technology from MIT.
  • Team ideally suited to technological task, but created entirely by accident.
  • Have worked well for four years.
  • Four founders have passed up well-paid and safe positions in industry to get this company going.
  • PlenOptika came from the Martha Gray Lab as well and share space with Leuko
  • Commercial input from MIT’s Venture Mentoring Service.
  • Advice to other scientist/founders form a company more than a year before leaving academia to apply for non-dilutive funding for the company. When the funding is granted then separate from the university to avoid conflicts of interest. Heard this from another founder.
  • Carlos advises potential founders to broaden their network to investors and people with commercial experience.
  • Super-connectors.
  • Being coachable and listening to advice.
  • Reporting frequently and succinctly is valuable. Having a narrative thread that ties one report to the previous one.
  • Reports as a way of eliciting help from investors.
  • Process of interviewing physicians took care to ensure candid opinions. Concrete steps to get unguarded responses.