The Hormoz Lab

Read the past.
Learn the rules.
Control the future.

Every biological system has a history, and that history shapes what it can become. We invent technologies to make these histories observable, develop mathematical models to discover how history determines fate, and use those discoveries to control cells, populations, and developing tissues.

Based at
Signals and molecular traces forming a branching cell lineage that flows into an organized living tissue

Histories unfold across time

HoursSignals experienced by a cell
DaysLineages formed during development
DecadesThe hidden growth of a cancer
MillenniaThe evolution of populations

How we work

History becomes useful when it reveals the rules of change.

01

Make histories observable

We engineer cells to record their experiences, watch cellular families across generations, and reconstruct the past from molecular traces.

02

Infer how history determines fate

We develop mathematics that reveals hidden states, transition rules, clonal fitness, and the local interactions that build tissues.

03

Control what happens next

We perturb biological systems to test the inferred rules, then use those rules to redirect cells, populations, and developing tissues.

Current questions

What histories can biology remember?

All projects
Sahand Hormoz and a lab member discussing a cell culture flask

Mentoring in the lab

Mentoring and lab culture

“I see mentoring as a gradual transfer of scientific independence.”

Our lab is for scientists who want to cross boundaries between biology, engineering, mathematics, and computation. We do not expect students to arrive as experts in every area. We look for curiosity, rigor, and a desire to learn.

How we work together

Selected work

Recent ideas and technologies

All publications
arXiv2025

DiffeoMorph: Learning to Morph 3D Shapes Using Differentiable Agent-Based Simulations

A differentiable agent-based model learns local rules that cause cells to assemble into target three-dimensional shapes.

ICLR2025

Improving Graph Neural Networks by Learning Continuous Edge Directions

A graph neural network learns the direction of information flow directly from data.

IEEE Transactions on Signal Processing2025

An efficient solution to Hidden Markov Models on trees with coupled branches

New mathematics for inferring hidden dynamics on branching cellular lineages.

2026–2027 rotations

Build experiments and theory together.

We are recruiting Harvard graduate students who want to learn how biological history determines what happens next.

See rotation projects