# Universality of biochemical feedback and its application to immune cells

## TL;DR

This paper establishes a universal framework linking biochemical feedback in immune cells to the Ising model, enabling data-driven insights into cellular responses and molecule numbers without detailed molecular knowledge.

## Contribution

It introduces a mapping of biochemical feedback models to the Ising model, allowing extraction of thermodynamic parameters from biological data.

## Key findings

- Successful application to mouse T cell fluorescence data
- Revealed differences in drug response mechanisms
- Enabled inference of molecule numbers from fluorescence intensity

## Abstract

We map a class of well-mixed stochastic models of biochemical feedback in steady state to the mean-field Ising model near the critical point. The mapping provides an effective temperature, magnetic field, order parameter, and heat capacity that can be extracted from biological data without fitting or knowledge of the underlying molecular details. We demonstrate this procedure on fluorescence data from mouse T cells, which reveals distinctions between how the cells respond to different drugs. We also show that the heat capacity allows inference of absolute molecule number from fluorescence intensity. We explain this result in terms of the underlying fluctuations and demonstrate the generality of our work.