JWST three-colour image of NGC 4321 overlaid with HCN contours. The background image is a three-colour composite using the MIRI and NIRCAM instruments observations (red = F770W + F1000W + F1130W + F2100W, green = F360M + F770W, and blue = F300M + F335M) taken from the PHANGS–JWST treasury survey (Lee et al. 2023). Overlaid HCN(1–0) contours (new data presented in this work), tracing the dense molecular gas are drawn at S/N levels of (2, 3, 5, 10, 20, 30, 50, 100). The sites of star formation (reddish hues) appear spatially well correlated with the dense gas traced by HCN. This image is rotated by 21° with respect to the right ascension-declination plane as indicated by the north (N)-east (E) coordinate axes in the bottom left. The bottom right image shows a rgb image (red = F814W, green = F555W, blue = F438W + F336W + F275W) from PHANGS–HST (Lee et al. 2022).