The purpose of the NCI Pathway to Independence Award for Early-Stage Postdoctoral Researchers (K99/R00) program is to increase and maintain a strong cohort of new and talented, NCI-supported, independent investigators. This program is designed for postdoctoral fellows with research and/or clinical doctoral degrees who do not require an extended period of mentored research training beyond their doctoral degrees. The objective of this award is to facilitate a timely transition of these fellows from their mentored, postdoctoral research positions to independent tenure-track (or equivalent) faculty positions. The program will provide independent NCI research support during this transition to help awardees to launch competitive, independent research careers. Researchers in the scientific areas of cancer control, cancer prevention and cancer data sciences are especially encouraged to work with their institutions to apply. This notice of funding opportunity (NOFO) is for basic science experimental studies involving humans, referred to in NOT-OD-18-212 as prospective basic science studies involving human participants. These studies fall within the NIH definition of a clinical trial and also meet the definition of basic research. Types of studies that should be submitted under this NOFO include studies that prospectively assign human participants to conditions (i.e., experimentally manipulate independent variables) and that assess biomedical or behavioral outcomes in humans for the purpose of understanding the fundamental aspects of phenomena without specific application towards processes or products in mind. Those not planning an independent clinical trial or basic experimental study with humans, or proposing to gain research experience in a clinical trial or basic experimental study with humans led by another investigator, must apply to the 'Independent Clinical Trial Not Allowed' companion NOFO (PAR-23-286). The number of awards is contingent upon NIH appropriations and the submission of a sufficient number of meritorious applications.