Urine samples no longer need refrigerated shipping; customers can return kits in a prepaid envelope from any postal mailbox in Japan

TOKYO, September 4, 2026 - Craif Inc., a bio-AI company developing a urine analysis platform for early detection of cancer and other diseases, has started supplying a new miSignal Light test kit whose urine sample can be stored and shipped at room temperature. Customers collect the sample at home, seal it in the return envelope included in the kit and drop it in an ordinary postal mailbox. The earlier kit required refrigerated shipping. Coverage is nationwide in Japan, excluding certain remote islands where collection and sale are not available.

Craif is a bio-AI company founded in 2018 that develops cancer detection from urine. Its analysis platform, NANO IP (NANO Intelligence Platform), detects biomarkers including DNA and microRNA in urine and other body fluids, and the company pairs that detection with AI to read cancer risk. miSignal Light is the lightest test in the miSignal series.

What changed

The room temperature kit is being introduced first through Craif's official online store. Amazon and Rakuten Market listings are switching to it in sequence. The change applies only to miSignal Light bought online. miSignal Light sold through pharmacies and medical institutions still requires refrigerated storage and shipping, as does miSignal Scan, the urinary microRNA test Craif sells alongside it. Kits that arrive with a return box rather than a return envelope must not be posted in a mailbox. They have to be kept cold and shipped refrigerated.

Why it matters

The change is possible because the sample stays stable at room temperature through the regular postal system. Because the kit no longer requires a cold chain, customers can return their sample from anywhere with a mailbox, with no courier pickup window, refrigerated packaging or scheduled return. Craif designed the change for people who have found testing difficult to fit into their schedule or reach from where they live.

In Japan, the lifetime probability of being diagnosed with cancer is 61.1 percent for men and 50.1 percent for women, roughly one person in two. Against a national target of at least 60 percent participation in cancer screening, none of the stomach, colorectal, lung, breast or cervical screening programs has reached it.

Sources: National Cancer Center Japan, Cancer Information Service, Latest Cancer Statistics, cumulative cancer incidence risk based on 2023 data; and the Comprehensive Survey of Living Conditions.

About miSignal Light

miSignal Light measures a urinary metabolite to give a whole-body cancer risk reading. Cancer cells metabolize differently from normal cells, and that difference shows up in the metabolites excreted in urine. The test detects cancer risk from as early as stage 1. It is not specific to any one cancer type, and it does not give risk readings by cancer type. It involves no dietary restriction and no physical burden beyond collecting a urine sample at home.

miSignal Light is not a medical device. It determines risk through statistical calculations based on the information analyzed. It is not a substitute for a medical diagnosis of whether a person has cancer, and a low-risk result does not mean that cancer is absent or that a person will not develop cancer in the future.

About Craif

Craif is a bio-AI company founded in 2018 that develops non-invasive tests for the early detection of cancer. Its platform combines proprietary biomarker detection from urine and other bodily fluids with AI to assess disease risk. Building on one of the world's largest urine datasets, Craif aims to create a urine analysis platform that detects a wide range of diseases early, with cancer as the first step. The company is based in Tokyo and operates a wholly owned laboratory in San Diego, opened in 2026. Learn more at craif.com.

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